One of the best selling books in America right now is old, expensive, and as recently as Monday couldn’t outsell a history of library subject headings. Yet The Thrill of the Chase—a silm, episodic memoir self-published by a white-haired retiree in Santa Fe—is now in the upper third of the Amazon 100 List, surpassing books by George Saunders, Laura Hillenbrand, and Supreme Court Justice Sonia Sotomayor. It peaked at number 15 on Tuesday night, trading places with Fifty Shades of Grey and The Perks of Being a Wall Flower, among other hits of the nightstand. What gives? Oh, nothing … just a million-dollar marketing gambit, involving an amazing race for hidden treasure and the biggest grave-robbing case of all time.

Last summer, I profiled Forrest Fenn, the quixotic author of The Thrill of the Chase, who walked me through his decision to secret a chest of gold, jewels, and precious artifacts into the mountains “north of Santa Fe.” He peppered his memoir with clues to the location—including coded directions in a 24-line poem that ends: “So hear me all and listen good,/Your effort will be worth the cold./If you are brave and in the wood/I give you title to the gold.”

But in our days of conversation, he inevitably shared a few more, passing along unpublished autobiographical writings, old newspaper clippings, and copies of prior self-published books, all of which contain personal elements. He also introduced me to his family, toured me around his gallery, and taught me to dig at the historic pueblo he owns outside of town. I buttressed all this with more than a dozen of interviews of my own, tracking down some of Fenn’s old friends and business partners, former members of law enforcement, and churning through hundreds of far-flung documents: press clips, old books, and federal records.

Yes, Uncle Sam was on the story as well, pursuing Fenn as a person of interest in a multi-state investigation into grave-robbing and artifact theft in the Southwest. They raided his house in 2009, and the case remains open today, according to the FBI and the U.S. attorney’s office in Albuquerque. After my piece was published—dubbing Fenn “The Real Indiana Jones”—the cagey collector says he turned down a string of broadcast hits, and soon enough his book faded. Until now.

This week Fenn appeared on The Today Show, and NBC Nightly News touting the treasure hunt, and reigniting the search for his gold. The appearance set off a Fenn frenzy, crashing his personal website and creating a run on his book, which until now had been a marginalized curiosity, sold through a single independent book store in Santa Fe. As of this writing, Amazon listed one copy left for sale, $45, and other sites advertised “used” volumes for three times as much. Fenn himself has gone back for a new printing.

So as book orders are filled over the next few days, I thought I’d re-read along with everybody, and tell you what I know. I’ve been dying to shake out my notebook since last summer, and what follows is the start of an annotated guide to The Thrill of the Chase, and to Forrest Fenn, a man every hopeful hunter will need to know to decode the poem and find the gold.

First, the disclaimer: Fenn is a hard man to know. How hard? His wife of more than half a century says not even she knows him, not really, and Fenn says heck “I don’t know myself.” He was born in central Texas, but he doesn’t know how his father ended up in Texas, or who the first Fenn in America was, or even where the name Fenn comes from. “It’s Irish or Scottish or something,” he said, waving away the question. In our conversations, he seemed to like his lack of history. It seemed to set him free to create himself, which he does in The Thrill of the Chase.

The pleasure is in separating Fenn fact from Fenn fiction.

His memoir is a drifty, disorganized thing. One imagines him dropping the pages on the way to the printer, losing a few in the wind, and binding the rest in whatever order he picked them up. But it doesn’t matter. What makes this treasure scheme so exciting—and so unnerving for some—is the figure of Fenn himself: a man who may be America’s last great collector, an amateur digger and self-taught everything, smarter than the average archeologist, savvier than a rude tomb-raider, and more aggressive than both.

Read the first half of The Thrill of the Chase closely. It covers the childhood through college years, the era when Fenn became Fenn. That’s important, because Fenn is a sentimental guy, and he told me he hid the treasure in a place he has known for years.

He describes a string of such places in the book. As a boy, he lived in a wood-frame house, with a cow in the back, freshly shot bird for dinner, and homemade soap for the bath. At night, during the warm months, he slept with his pillow on the open windowsill, breathing in cottonseed from the mill and listening for the mail train. Sometimes he snuck out to watch the gypsies down by the tracks, or to walk through the cemetery, sit on a grave.

But at this point in the text, we’re still in Texas, a place decidedly not “in the mountains north of Santa Fe.” Sure, Fenn once pointed a blogger in a slightly different direction, teasing the treasure as being “more than 300 miles west of Toledo.” But he tells me the line was “said in jest” and that “there is no clue there.”

Most revealing in the first half of the book: the way Fenn conducts himself. He spent his boyhood “learning where the edge is,” as he writes, defying his father and relying on himself. He scavenged the locale dump, built a bike, and sold it to one of the kids in the brick houses. He also started collecting things. He filled a whole room in the barn with magazines, and built a ball of string too wide for his bedroom door.

He collected Indian artifacts, of course, and it was this—picked up with his father—that lead him to a lifetime of keeping his eyes on the ground, his hands in the dirt, pursing artifacts of the past. “I get a thrill when I pick up something that hasn’t been touched in a thousand years,” Fenn told me during my visit.

Those two points combined—the rebelliousness, the love of antiquities—point toward a hiding place on public land, where the ground is lumpy with centuries of human debris. The Thrill of the Chase is about giving a hands-on experience to the public-at-large. You could say Fenn’s whole life is about that ethos. He built the thrill into his gallery—housing 19th-century landscape paintings priced higher than some state lotto jackpots—and his home, where I ran my finger over the lip of six perfect pre-Columbian pots and felt the point of an 800-year-old needle and a mescal knife for eating cactus. “Please touch,” he said emphatically. “I am responsible.”

But be forewarned, dear reader: this is a complicated gesture, one that might lead some people to court and others to jail. Fenn says he went into the mountains north of Santa Fe. He apparently didn’t go far, and the conditions were not that extreme. “People who go looking for the treasure should not search where a 79- or 80-year-old man could not take it,” Fenn told me.

He and his wife have driven to Montana, through Colorado and Wyoming, in the last few years, and another friend of Fenn’s—the writer Douglas Preston—recalls hearing Fenn talk about northern Arizona. In choosing the location, Fenn himself told me he was thinking “10,000 years down the road ... I considered mudslides, forest fires, earthquakes, and floods.” And yet he maintains that the treasure is readily accessible to him, even today. “I could go right there.”

The problem in all this is title: who owns the land where Fenn hid the treasure? Not Fenn, or so he tells me. He won’t confirm that it’s on federal land—“too big of a clue,” he says—but he feels darn entitled to use such land as he pleases, no matter how sacred ground. “I own the government,” he told me. “I’m a taxpayer.”

Would he dig Ground Zero, where the World Trade Center once stood? He’s not opposed to idea. “Why shouldn’t you go in there and pick up a piece of cement?” he asked me rhetorically. “They took all the bodies out of there.”

But if Fenn hid the chest on government land it could be a felony to remove it, since everything on government land by definition belongs to the country, to all taxpayers, not just a brazen fellow hoping to play finders-keepers. And if Fenn hid the box on private land, well, as Fenn himself will tell you, the owner of the land is the automatic owner of the box. “There’s no place that you can put [the treasure] that under the right circumstances there are not complications,” Fenn told me.

But can you at least assure people they won’t get arrested? Or that they won’t get sued and lose the money? “I’m not assuring people of anything,” Fenn admitted. “I went out there and hide a treasure chest, and they can go get it. That’s it.”

And that’s it for me, too, until the next entry, when we zero in on Yellowstone Park, perhaps Fenn’s favorite place in the world, and decode the poem line-by-line. If you have questions for me, put them in the comments section. I’ll be answering.