In January of this year, we landed in Orlando, straining our eyes to see what was happening during the excavation of an empty lot on a lake. We were in Florida to track down a lead — one that was probable enough that the FBI was the one ordering the excavation.

That lead blossomed from a tip Boston Globe reporter Stephen Kurkjian received in 2016 from Alonso Esposito. Now out of witness protection, Alsonso Esposito — the name Bobby Luisi adopted — wanted to share what he knew about the Gardner Museum’s stolen art.

Formerly a Boston mob boss, Luisi had been close with Bobby Guarente. You know, the Bobby whose name keeps popping up because of his connection to so many of the men mixed up in the FBI’s investigation of this heist. His widow at one point claimed Guarente had the art before handing it over to Bobby Gentile. The tip Luisi wanted to share was from a brief conversation with Guarente in the late 1990s when they were selling cocaine in Boston. One night, they were watching TV together and a story came on about the Gardner heist. Guarente tells Luisi that he knows where the art’s buried — under a concrete floor in Florida.

Based on this passing mention between two mobsters, one dead, the other known to embellish, Kurkjian started digging. He went through his files on Guarente to find an address that had missed before. A DEA report placed him at a Florida address in the early ‘90s. The house had been torn down back in 2007 — all that remained was a little under an acre of cleared land that sloped down to a sparking lake.

Neither the contractor who had torn down the house, nor the one who had broken up the swimming pool, had found a Rembrandt or anything even approximating a hiding space underground. But the original phone lines still ran underground. If the phone lines were still there, it was conceivable that the contractors left something else behind as well.

With the landowners OK to find out what was down there, WBUR and The Boston Globe hired an engineering firm to scan the lot in December of 2017. The geologist, who did not know we were on the hunt for buried treasure, found an anomaly four to six feet underground — proving that the spot warranted further investigation, namely an excavation.

But, given our tip that the stolen Gardner artwork could be down there, this was a potential crime scene and we had to involve the FBI and museum. That’s when things got really complicated.

As December ticked on, the lot’s owner was anxious to find out what was underneath it. The Gardner Museum’s doubled reward, at $10 million, was scheduled to expire at midnight on Dec. 31 and return to $5 million. He reached out to the museum’s security director Anthony Amore separately to register the tip before the New Year. And that’s when we ran headlong into a wall of silence — from the FBI, the landowner and the museum.

On Jan. 31, 2018, federal officials ordered the excavation of a lot in Orlando based on a mobster's tip that the Gardner's stolen art might be buried underground. The investigation turned up empty. (John Tlumacki/Boston Globe)

We made our best guess and staked out the lot on Jan. 31, 2018. Early that morning, we found all sorts of equipment and officials. We watched from across the street as a group of FBI agents and other investigators watched as a backhoe dug and dug. This was essentially the federal government agreeing that there is a possibility of a recovery here.

But what does it mean that after 28 and a half years, the FBI still hasn’t solved the case? Why does solving it look so hard? All those unreliable narrators we've told you about are part of the reason. These con men and criminals, by turns tragic, comical and chilling. Dead or alive, each has been a pretender to the throne of the perfect crime. But was the Gardner heist a perfect crime? Or has it just been an imperfect investigation?

Subscribe to our newsletter for the latest updates, join our Facebook group to discuss the investigation and if you have a tip, theory or thought, we want to hear it.

This episode was adapted for the web by Amy Gorel.

Transcript:

KELLY HORAN AND JACK RODOLICO: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16.

RODOLICO: Wow there's...

HORAN: There's 16; 16 to 20.

RODOLICO: Sixteen to 20 people over there. Do you think it feels as tense over there as it does over here?

HORAN: Oh my god. Does it feel so tense for you right now?

RODOLICO: Yeah. Yeah, it does. I feel like it's very, very quiet.

HORAN: I can almost not breathe.

HORAN: Jack and I are in Orlando, Florida, on the porch of a family we met an hour ago. There are potted plants, a leather couch, a Harley Davidson — and us, squeezed into the middle of it all. The people you just heard us counting are across the street, on a vacant lot, where a backhoe has been digging a giant hole all morning. The engine is cut now, and they are standing around that hole, staring down at something.

HORAN: They're crouching now. They're bending.

RODOLICO: This is such an odd little scene. All of them standing over there looking at the hole, and all of us standing over across the street just staring at them.

HORAN: Standing over here. Looking at them, looking at the hole.

RODOLICO: Looking at them, looking at the hole.

HORAN: FBI agents in khakis and fleeces oversee the excavation. And we’re here, watching in a state of heightened anticipation and recording all of it, because they are digging up our lead.

RODOLICO: Digging. I see him throwing dirt out of the hole.

HORAN: Yup. We've got two more shovels, three more shovels in the hands of the FBI.

HORAN: The agents poke at the bottom of the hole. They’re in it up to their shoulders. Whatever is down there, the shovels aren’t enough to unearth it.

RODOLICO: Somebody's climbing back into the digger.

HORAN: The digger is going back to work.

HORAN: So why are we color-narrating the movements of a backhoe and getting all worked up over a hole in the ground? Because 28 and a half years since the greatest art heist in history, without a single arrest or recovery in the Isabella Stewart Gardner Museum robbery, the art could be anywhere — even in a hole in Orlando.

RODOLICO: From WBUR and The Boston Globe, this is Last Seen. I’m Jack Rodolico.

HORAN: And I’m Kelly Horan. This is Episode 9: "The Big Dig."

STEPHEN KURKJIAN: They are pursuing something right now. They are seeing something.

RODOLICO: Our colleague from The Boston Globe, Steve Kurkjian, began developing the lead that led us to Orlando, Florida, in 2016. Steve is the consummate skeptic. All those yarns spun by all those criminals about what they might or might not know about the Gardner art? Steve doesn’t buy any of it. But this lead — this lead he likes.

HORAN: And, as he stands across the street from a 23-ton backhoe that’s delicately peeling away layers of earth, Steve likes this lead a lot.

RODOLICO: This now vacant lot was once a rented, warm weather getaway for a Boston gangster who tops the list of Gardner suspects. We’ve told you about him before. His name is Bobby Guarente. He’s the one who had that hiding spot in his house in Maine. And on a Venn diagram of Gardner heist suspects, Bobby Guarente would be in the middle. Before he died, he was mixed up in one way or another with so many of the men named in connection to either robbing the museum or trafficking the art.

HORAN: In May 2016, Steve Kurkjian got a call from a retired mobster who had been close with Guarente. The caller’s name, Alonso Esposito, didn’t ring a bell. But then he told Steve that was just the name he took when he entered witness protection.

KURKJIAN: So he said, "No, no, no, my name is Bobby Luisi." And I was really shocked and very excited because I felt he was a very important person.

BOBBY LUISI: Can you hear me?

HORAN: I can hear you great. Can you hear me?

LUISI: Yes, I can.

HORAN: For a guy whose life depended on adopting a new identity and back story, Bobby Luisi doesn’t seem to recall his gangster past with regret. Relish seems a better word.

LUISI: You know, I was like a Tony Soprano. I had all the goomahs. I had the money, the cars, the nice clothes, and in my neighborhood, I was a star. There was no doubt about that. You know, I had a little charisma. I flashed money around. I took care of everybody. And it was a nice way of life for me.

HORAN: Luisi’s nice way of life came at a cost. People close to him murdered his father and half-brother. He lost years of his life in prison for trafficking cocaine. But he emerged from witness protection a few years ago dangling a tip about the stolen Gardner art. In the late 1990s, Luisi and Bobby Guarente were selling cocaine in Boston. They shared a safe house in a suburb. And one night, as the two were watching TV, a story came on about the Gardner heist.

LUISI: And they were talking about the artwork. And he says, "I know where the art's buried." He said it's in Florida under a concrete floor. He didn’t say where in Florida. He just said it was buried under a concrete slab in Florida. This is what I was told directly from his mouth.

HORAN: And based on how well you knew Bobby did you feel like he was just, you know, posing and trying to show off, or did you really feel like, "Wow, he must know something."

LUISI: Oh, no, no. I would believe him 100 percent. You know he's a thief, a murderer. That's what he was, you know. So I really do believe what he told me.

HORAN: When Steve Kurkjian learned this in 2016, he wondered: “What am I supposed to do with this?” A passing mention almost 20 years earlier between two mobsters — one dead, the other known to embellish. Where do you even start with a tip like that?

KURKJIAN: Well, I had already done my due diligence on Guarente and I pulled out my biography file on him.

RODOLICO: Steve knew Guarente had lived in Boston and Maine. But buried in his paperwork on him, he found a DEA report with an address he’d never previously noticed.

KURKJIAN: And there was one place in Florida. So I said, "Mmmm, not eureka yet, but I think that's the place we ought to start looking."

RODOLICO: In a piece he co-wrote with Shelley Murphy for The Boston Globe in 2016, Steve all but published the Orlando lot’s address. If news of its existence had piqued the FBI’s interest, we don’t know. We do know that the FBI never contacted the owner of that land at the time. Something about that lot still bugged Steve. In August of 2017, Steve went to Florida to see it for himself. The house had been torn down a decade earlier. All that remained was a little under an acre of cleared land that sloped down to a sparkling lake.

KURKJIAN: And there are houses across the street. And people coming and going in the houses — so, which was good.

RODOLICO: Steve started knocking on doors.

KURKJIAN: OK, I am here with Roque Cartagena, and we’re on his front porch on a beautiful, sunny day.

RODOLICO: Roque Cartagena’s front porch looked out over the empty lot, which had been vacant since he'd lived there. But he knew a guy who might remember the house where Guarente once vacationed.

ROQUE CARTAGENA: Ah-ha! Luigi, what’s up, boy?

RODOLICO: A neighbor, named Luigi Ferrari.

CARTAGENA: Not much man, not much. Listen I’m calling you because there is somebody here. He’s a reporter.

KURKJIAN: Can you hear me, it’s Steve Kurkjian.

LUIGI FERRARI: Steve Kurcher. OK, Steve, my name is Luigi. Nice to meet you.

KURKJIAN: Great to hear from you.

RODOLICO: Steve explained a little bit about what he wanted. You know that empty lot? Maybe there’s $500 million worth of art buried there. That kind of thing.

FERRARI: Uh, was born on that street in 1974. I’ve played on that lot since I was a child. And I pretty much know that area like the back of my hand.

RODOLICO: The next day, Ferrari walked Steve right onto the empty lot.

KURKJIAN: Let’s just take a walk down.

FERRARI: Sure.

KURKJIAN: The house was how far down? Was this a driveway that we're on now?

FERRARI: There really never was a driveway before. It was actually just a...

RODOLICO: Luigi Ferrari turned out to be an unofficial neighborhood historian. He remembered the house — it was sleek, modern, maybe a little gaudy.

FERRARI: There used to be a tiki bar. It was a big tiki bar. It had a — I mean, back in the '80s it had a TV and all kinds of amenities. Yeah, they had — the pool was gorgeous. It had table tops, which were mosaic, that the water would actually come up the base of this, and just percolate over top of the mosaic, keeping everything looking beautiful and white and everything. This is something that you didn’t see back then, you know. Very nice.

RODOLICO: Like something a gangster might like. The back of the house, facing the lake, was all glass. The lawn rolled down to a white sand beach. Ferrari didn't remember Guarente, who'd rented the house in the early '90s.

HORAN: In 2016, Steve tracked down two contractors who were in a position to know what was below ground on the lot. One had torn the house down in 2007. The other had broken up that beautiful swimming pool. Neither had found a Rembrandt, or anything even approximating a hiding space underground. For Steve, it was starting to feel like a dead end.

FERRARI: I can tell you this — it hasn’t been dug up right here.

HORAN: Until Ferrari noticed something curious.

FERRARI: Here’s the original phone lines. This is the original phone lines, right here. These are all, still all attached going under the ground.

HORAN: If the phone lines were there, maybe the contractors who tore down the house left something else behind. Steve thought: "Could the Gardner art be down there? Buried in Orlando, Florida? Maybe." There was just one way to find out.

KURKJIAN: There's no way I'm going to be able to find anything unless I dig up the lot. And it's a big lot!

HORAN: Not only that. Steve had yet to find the owner of that lot.

KURKJIAN: So the second thing I did the next day is I drove into his — surreptitiously — into his gated community, the owner. And I left a note in his mailbox. I found his mailbox and I banged on the door. He doesn't hear me! He's not coming out. So I said, "This is gonna ruin it."

HORAN: Just as Steve was willing to let it all go, the landowner reached out to him. Steve revealed why he was interested in his lot. And then, through an attorney, Steve got the go ahead: Find out what’s down there.

KURKJIAN: So this piece of equipment is what that’s being used?

BRAD DUPKE: This is the ground-penetrating radar.

HORAN: In December of 2017, WBUR and The Boston Globe hired an engineering firm to scan the empty lot for evidence that something worth digging up might be beneath the surface. This is the lead geologist, Brad Dupke, who did not know that he was looking for buried treasure. He pushed what looked like a lawn mower over the ground where the house once stood.

DUPKE: The four-wheel cart houses the antenna. It's a transmitting, receiving antenna and this is the computer part of it.

HORAN: Dupke used two different technologies — radio and electromagnetic waves — to determine whether there was something not naturally occurring below the ground’s surface. If both types of waves identified an anomaly in the same spot, Dupke explained, then that spot warranted further investigation.

KURKJIAN: And in late December we get the report and eureka! They do see something four to six feet below the surface that they said they could not explain.

HORAN: There was something down there. Dupke said he knew exactly where it was: below where the back right corner of the house had been. It was rectangular, like a box.

DUPKE: We have a target. Let's see what that target is.

KURKJIAN: Brad, do you mean similar survey work or excavation?

DUPKE: Excavation, like a test pit, digging it up.

HORAN: There was just one problem. This lead wasn’t about just any anomaly buried underground. It was about the Gardner art, which made this Orlando lot potentially a crime scene. And that meant, we could not do this dig — not on our own. The FBI needed to know about it. So did the museum. We didn’t want to risk damaging some of the world’s most valuable stolen art. So we did what we thought we were supposed to do with the information we now had. And that’s when things got really complicated.

RODOLICO: Steve Kurkjian’s reporting on the lot in Orlando was playing out with a very loud clock ticking in the background. In May of 2017, the Gardner Museum announced it was doubling its reward for the return of the missing art, from $5 to 10 million. That reward would expire, they said, at midnight, Dec. 31. The guy who owned the Orlando lot became motivated to find out what was under it. So with the knowledge that the geological survey detected a rectangular shape beneath the surface — a rectangle the perfect size to hold a five-by-four foot Rembrandt — and with the landowner eager to register his claim before the reward reverted to a mere $5 million, Kelly went to the Gardner Museum to see head of security Anthony Amore.

HORAN: It was Dec. 28, 2017. With just three days to go until the museum’s doubled reward was set to expire, Amore had been barraged with tips from all over the world. And here I was with one more.

HORAN: OK. So my team might have a lead that we would — we feel at this point that we'd like to share it with you, that we feel compelled to share it with you.

HORAN: Amore had long suspected that Bobby Guarente had once possessed the art, so I figured that he would have either already run this lead down, so he could dismiss it, or it would pique his interest. If our lead was good, I wanted the FBI to be able to do their job. And I wanted us to be able to do ours. But knowing that Amore was obliged to take our tip straight to the FBI, and fearing that they would shut us out, I was careful. So I began cautiously. I said, “We have a source. We can’t say who. He owns some land. We can’t say where.”

HORAN: The fear that I have as a journalist who's been covering this is that I have no knowledge of how the FBI works because they have refused to sit down with us. And what I don't want to have happen is to say, give you an address, and have our access to this site cut off.

ANTHONY AMORE: I would say that the museum, the paintings, are exponentially more important than a podcast.

HORAN: OK — that hurts. But I understand. [Laughs.]

AMORE: It's true.

HORAN: Of course it's true. Of course it's true.

AMORE: I can't speak for what the FBI will do, what they'll say. I just know that they're committed to a recovery just like I am. But I can't say, "Oh yeah, well they'll let the media be involved." I mean, that's not — my history with them tells me that whatever their decision is is going to be the one that I think is the way to go.

HORAN: It was tense. And after I left Amore’s office, things got even more tense. The landowner got jumpy about that expiring reward. His lawyer, who had been in frequent contact with us, went around us and reached out to Amore, to register the claim before the New Year. Amore deemed the tip "credible," and he shared it with the Boston FBI. And that’s when we ran headlong into a wall of silence. Amore stopped communicating. The Orlando landowner and his lawyer stopped returning our phone calls and emails and texts. We’d been shut out, exactly as I’d feared. But all that silence spoke volumes. We sensed that the dig was imminent. And we presumed that the FBI didn’t want us to know that.

RODOLICO: When communications blacked out, we guessed. In the early hours of a Boston snowstorm, we flew to Orlando. And on the morning of Jan. 31, 2018, we hopped into our rental car and drove straight to the lot.

RODOLICO: Oh there's all kinds of digging equipment. Take your headphones off. I'm going to keep my mic low.

HORAN: Yeah, keep your mic low. So we've got — we've got a huge backhoe.

RODOLICO: There's a big backhoe on the street. Holy crap.

GPS: Your destination is on the right.

RODOLICO: We’d guessed right. The gate to the lot was locked. FBI agents were present. It was happening. Now, we told you that we staked out on a neighbor’s porch. But we had to get there first, preferably without the FBI spotting us.

HORAN: OK. Here we go.

RODOLICO: We parked well out of sight. We shoved our mics into our bags. And we walked right past the dig site and into Roque Cartagena’s house. A photographer from The Boston Globe, John Tlumacki, was slung low in an SUV with tinted windows, taking photographs out the back. Inside, we peered through drawn curtains, trying to make sense of the movement across the street.

HORAN: The glare from this lake is making it really hard to see through these binoculars. But someone's — someone's plotted out the dig area. He's marking the grass right now. He's walking the perimeter. It does look to be about 15 feet across.

HORAN: Steve, Jack and I were now in the house with Roque Cartagena.

CARTAGENA: You can open the refrigerator and grab whatever you want.

HORAN: And his mother was there too, and his daughter, and grandkids, and cats, two Doberman Pinschers, and a very chatty bird. And about an hour into our stakeout, around 9:30 in the morning...

HORAN: Oh, they're digging!

RODOLICO: Whoa.

HORAN: The orange Doosan.

RODOLICO: The digger's on the move. Oh my, god!

HORAN: ...is in motion.

RODOLICO: This is the spot. This is the spot.

HORAN: There! This is the spot. They are moving a lot of earth right now.

HORAN: We overheard Steve say to himself, “I can’t believe this is happening.”

KURKJIAN: This is... This is a culmination of, you know, eight months of good work. I’ve been on that lot by myself just wondering what's below the surface and, look, the federal government is agreeing that there is a possibility that there is a recovery that could be gained here.

HORAN: We slipped onto the porch. We could see the whole lot, the digger, the agents. The Globe’s photographer was now on Cartagenas’ roof, perched there, shooting the action with a telephoto lens.

HORAN: They've stopped the digger. They're going in now with shovels.

RODOLICO: Throughout the morning, a pattern emerged. The digger dug, then stopped.

HORAN: Everyone has gathered around the hole and it looks like this crowd has doubled.

RODOLICO: People stared into the hole. Then the digger started up again.

RODOLICO: Somebody’s climbing back into the digger.

HORAN: The digger is going back to work.

RODOLICO: They've got an eight foot tall pile of dirt that they're just adding more soil to.

RODOLICO: Remember our geologist, the one who identified the rectangular object below the surface? Well, now we could see him overseeing the dig. He was in the backhoe. Clearly, he was no longer our geologist. He was the FBI’s. He was standing next to the hole, drawing a big box with his fingers over his head. Our new resident expert, Roque Cartagena, who was hours late for work at this point, was huddled on the porch with us, guessing at what they were seeing down there.

CARTAGENA: Yes, they did find something, I believe.

RODOLICO: And in these tense, anxious moments, we noticed that Steve had left the porch and was standing in plain sight on the sidewalk.

RODOLICO: Steve's getting jittery. I can't blame him.

HORAN: I can't believe he hasn't climbed the fence.

RODOLICO: Any moment.

KURKJIAN: [In the distance.] Come on! Talk to me!

HORAN: The man who owned this lead, who’d done all the reporting that put the FBI on this lot, who had spent two years turning a tip from a gangster into a credible lead in the Gardner mystery, was restless.

RODOLICO: Steve is losing it. Yeah. All of us are being discreet, somewhat, on the porch. We think John the photographer is up on the roof. Steve Kurkjian is standing on the sidewalk in broad daylight, looking back at us every once in awhile saying very loudly, "They've found something. They've got something." He can't keep it together.

HORAN: I like his — I love his body language.

RODOLICO: He's inching closer to the road. He's almost standing in the street now.

HORAN: He's about to climb a fence. [Laughing.] And now he's got his iPhone out.

RODOLICO: He's got his iPhone out, over his head. Steve, can you come over here?

HORAN: Come over here so we can talk to you. Well then I'll go stand where you are.

KURKJIAN: Brad's in the hole. There's something. There is something there, Kelly.

HORAN: Steve looked the way we felt. The Gardner case does that to you. You get invested, obsessed even. We abandoned the porch and joined Steve on the sidewalk. It wasn’t like they were going to stop digging just because three reporters from Boston were there.

KURKJIAN: They. See. Something.

RODOLICO: They see something.

KURKJIAN: They see something. Wouldn't you say, Jack? They see something?

RODOLICO: They see something. They're gesturing a lot.

HORAN: Well, look how he's digging. He's-- he's-- It's very ginger, what he's doing. He's like tapping the ground. FBI agents conferring.

HORAN: They scraped at the bottom of the hole with rakes. You could lose a person in that hole. The digger started up again. We were still on the outside — still far from seeing what the people around the hole were seeing. It was practically killing us.

HORAN: So, how did we get here? I don't just mean a hole in the ground in Orlando, one that might or might not hold something as wide and as tall and as singular as Rembrandt's "Storm On The Sea Of Galilee." I mean, 28 and a half years after thieves made it look so easy to pull off what remains the single most valuable art heist ever, why does solving it still look so hard. All those unreliable narrators we've told you about are part of the reason. These con men and criminals, by turns tragic, comical and chilling. Dead or alive, each has been a pretender to the throne of the perfect crime. But was the Gardner heist a perfect crime? Or has it just been an imperfect investigation?

KURKJIAN: The FBI, in, with all of its skills, have used hard investigative tactics and that's gotten them to certain clues and certain suspects, but it hasn't gotten them to a single credible sighting of any of the artwork. And you're playing the same note?

HORAN: The FBI does have a pattern of setting up people of interest on tough charges, hoping they give something up about the Gardner heist in exchange for leniency. The 1999 sting on TRC Auto Electric yielded nothing. One suspect died in prison rather than talk to the feds. The others arrested are still behind bars. Then, more than a decade later, the FBI set up and arrested Bobby “The Cook” Gentile twice. The result? Nothing. Does this suggest that criminals hate the FBI more than they want their own freedom, or does it suggest that the FBI has been pursuing the wrong guys?

RODOLICO: Parsing the FBI's own statements about the case does make you wonder.

HORAN: In 2016, a retired FBI supervisor said that as of the last time he worked on a case, in 2001, the Boston office "knew no more than they did the day after it happened."

RODOLICO: That remark echoed what another agent told The Boston Globe in 2010 about the stolen art: "There hasn't been a concrete sighting, or real proof of life."

HORAN: And just five years ago, the head of the Boston FBI admitted, "We do not know where the art is currently located."

RODOLICO: We wanted the perspective of an outsider. Someone outside the Gardner investigation, but inside law enforcement. We landed in the small law office of Tom Dwyer — a local who climbed the ranks of the district attorney's office in the 1970s and '80s. Dwyer hopes the FBI solves the Gardner case, but he worries about what it means that they haven't.

TOM DWYER: I think the case was it’s so spectacular. When you see something that's so spectacular the public expects it to be solved. You know, it's, it's a longer period of time than solving most cases involving serial killers. I don't think people perceive that nothing is being done. I think people do believe that something is being done. They just don't know what it is.

RODOLICO: Which brings us to another conclusion: The Gardner investigation has a public relations problem.

HORAN: This case is so high profile — so sensational — that the Boston FBI’s silence in response to simple questions feels like ducking. They didn’t even respond to a short list of questions we submitted to them in writing. What is the public supposed to think?

AMORE: How would they know what's good for the investigation or not when they're not part of it, when all they know is what they’re reading in the newspaper?

RODOLICO: Anthony Amore bristles at any suggestion that the public might be critical of how the FBI has handled the case.

AMORE: It's bizarre to me. It's this feeling that the public has a need to know something that they don't. They just don't have a need to know. I mean, we're not holding things back to play, to play games or whatever. We're just trying to make every decision based on what is the best thing for the investigation.

RODOLICO: Amore has lost all patience with any suggestion that he, as the man leading the investigation for the museum, or the FBI, owes the public anything.

AMORE: To some people this is entertaining. It's a mystery. It's fascinating. It's alluring. People think art theft is sexy. It's you know, makes a great movie, that sort of thing. None of those things are what this really is. This investigation is about none of those things. It's strictly about getting the paintings back, and putting them back on the wall.

RODOLICO: Amore might not have a duty to the public. But doesn’t the Boston FBI? They've investigated the Gardner heist from behind closed doors. And they’ve done it that way for far too long. We believe it’s time for some transparency in the Gardner case.

HORAN: But there, on the sidewalk in Orlando, we were beginning to see things clearly.

KURKJIAN: What was that?

HORAN: Looks like broken concrete. Yep, definitely looks like concrete.

KURKJIAN: Come on. Here he comes. Here he comes. Come on over here.

HORAN: He's not coming to us.

KURKJIAN: Yeah, he is. Yeah, yeah.

HORAN: Is he? Why is this happening? Why are they coming now?

HORAN: With the backhoe dropping chunks of concrete on the grass, three people on the lot crossed the street and walked right up to us. It was the landowner, his girlfriend and his attorney, John Bill — the guy who’d stopped returning our phone calls in the run up to the secret dig. It was a little awkward.

JOHN BILL: So they're almost finished digging. And there's a little bit of the perimeter over there to the-- that they're still looking at, that's still within the perimeter of what they believed to be an area including those anomalies. But they've pretty much excavated down nine feet.

HORAN: It was just about noon. All told, the dig had taken less than three hours. It felt much longer. Time has a way of slowing way down when you think you’re unearthing masterworks of our civilization.

BILL: So, it was pretty much exactly where they thought it was, and the size of the object, and everything checked out except...

HORAN: Except, John Bill said, it was a septic tank. In that moment, there could not have been three words in the English language that we wanted to hear less: a septic tank. And just like that, it was over.

KURKJIAN: Oh man. In for nickel, in for a dime.

RODOLICO: After this whole day standing across the street, mysteriously peering across, I’m actually just going to walk onto the land now. Oh, yeah. That’s a septic system. Smells like septic, huh?

HORAN: Just a few hours earlier, three skeptical journalists, following a lead that was good as any in a case that’s stretched on for nearly three decades, had given themselves over to hope. And that says a lot. Because even as our collective disappointment smudged that good and open feeling right out, we’d felt it. We’d been propelled by it all the way to Florida, been a little high on it, even. So that’s what we’re left with — the hope that 13 long-missing pieces — a Vermeer, three Rembrandts, a Manet, a Flinck, five Degas sketches, a Napoleonic finial and a Chinese gu — will yet be unearthed on some other day, in some other place.

Before Isabella Stewart Gardner had even purchased the land on which her museum would be built, she reveled in the beauty of her art-filled home. On Jan. 20, 1898, Gardner wrote to her dealer in Florence, Italy, “Downstairs, I feel, are all those glories I could go and look at, if I wanted to! Think of that. I can see that Rembrandt any time I want to. There’s richness for you.”

And until that Rembrandt and the other stolen works are back in their rightful places at the Gardner Museum, we are all the poorer.

Last Seen is a production from WBUR and The Boston Globe. Digital content was produced in partnership with The ARTery, WBUR's arts and culture team. Read more on the Gardner heist from The ARTery.