[Warning: This story contains spoiler's from Sunday's episode of Veep, "Kissing Your Sister."]

Veep delivered a big surprise on Sunday night when it treated viewers to the finished product of Catherine Meyer's documentary.

Breaking format, the entire episode of the HBO comedy was aired in true documentary style to showcase the first daughter's "Kissing Your Sister: The Story of a Tie" — the "doc" she has been filming all season without any hint of the film ever coming to fruition.

"I wanted to try this idea where we didn't promote it and didn't tell anyone," Veep showrunner David Mandel tells The Hollywood Reporter. "A gazillion years ago, I did the backwards episode of Seinfeld ["The Betrayal"]. NBC promo’d the heck out of it and I always wondered: What if you turned the TV on and the show was just backwards — wouldn’t that have been more fun? So we tried to keep this as much a secret as we humanly could."

The documentary featured behind-the-scenes footage that only a first daughter (played by Sarah Sutherland) could have access to, revealing different vantage points to events that aired previously on the season. Mandel shot the first eight episodes, followed by the finale, so this episode could be a creative and fun way to wrap the season.

"We recreated things that connected to other things," says Mandel of the episode written by Erik Kenward (also of Saturday Night Live and Documentary Now!) "We did a lot of thinking about the whole season and: What are the scenes and moments where there’s something we can add on to? And we got to fill in a lot of the blanks."

The short film also continued to propel the current storyline along, taking viewers through the long-awaited Congressional vote and Selina's subsequent loss of the election, disastrously coupled by her failure to prevent a Tom James (Hugh Laurie) presidency.

"Her dream was to be elected president," says Mandel of Selina (Julia Louis-Dreyfus) serving as accidental president for the last year or so. "It wasn’t just nine episodes building up to that moment, it was the character’s entire career and life and hopes and dreams that were sort of shattered, and there’s nothing funnier than that."

Beginning with the biggest news of all, Mandel takes THR through 17 of the episode's somewhat heartbreaking and always hilarious reveals.

Selina Meyer Loses the Presidency

"There’s still a couple of looming questions to answer about her future but I will say this: She has lost the Presidency of the United States. We talked about it and we joked about it and we teared up a bit at the end. It was heartbreaking in a way. And Julia does that final scene with the tour group like nobody’s business: talk about a thousand different emotions running through the face and the eyes. Now, there is a larger question about a job that I think she doesn’t want to do. There is another job that she could take, but I don’t think she wants it." [Previews for the finale hint at Tom James offering Selina the position of Veep.]

She Had a Nervous Breakdown in the Past

"Selina says she was at a spa. Were there regular doctors involved? Hard to say. Who knows what that spa place was, but it does not seem out of character. I love the way Julia did that whole thing about her mom’s advice, about burying your troubles and you can see Selina’s brittleness there. It would not be surprising that she sort of had to take a month to pull herself together when she lost her first election for Congress back in the day when Catherine was a little girl. But it also raises questions about what might happen if Selina loses another big election."

Mike McClintock Is About to Get Fired — and He Has No Idea

"The moment where Selina leaves and Mike ducks back in and wants to know if there’s a meeting about him. When we first shot that, we didn’t keep going. We came back when we were shooting this episode and basically recreated it with Julia shooting it from outside. We liked the whole idea that they’ve been trying to fire Mike the whole season, which, by the way, makes a lot of sense given his amount of screw-ups. You expect a certain amount of things when she’s the vice president but when she thinks she’s going to be the president — she needs someone better doing some of these jobs. That always felt like one of those things where the audience is maybe wondering: How does this guy save his job all the time? And the honest answer is, he doesn’t. He’s going to lose his job."

Gary Removes the Green Room's Selina-Tom James Sex Couch

"You can watch that interview with Tony Hale — which is just really enjoyable about him talking about how everything’s going to be fine — and you can enjoy it and if you don’t realize that’s the Green Room and that’s the couch, that’s ok. But if you do realize what it is, it’s that much the better."

Charlie Baird Returns — Naked

"I love John Slattery walking out during Selina's interview, just another moment that's there if you want it. There’s a rough chronology to the interviews that kind of takes place throughout the season, so that’s early on when they’re still together. Some of the fun for the diehards out there will be to really sit down and figure out exactly when everything was. We tried to be very scientific about it."

MeeMaw Gets an Obit (something THR flagged from Selina Meyer's social media)

"We did it for the documentary, but realized we could use it for the web without anyone ever realizing it would eventually be used for the documentary. That’s one of the fun things we’ve been doing this year. When you read the obit, there aren't a lot of joke jokes in there, but the fun of it is the number of clubs and social events and things that she was a part of. So, if you’re familiar with society obituaries, it’s a real society obituary."



Catherine and Marjorie Break Up (Because Marjorie Isn't Out to Her Family) and Get Back Together

"We wanted to use the documentary to fill in some of the parts that we jumped over in the regular episodes with Marjorie and Catherine. You met Marjorie and she existed and then she kind of surprised us in episode six when Catherine told her mother about them, so that was an opportunity to fill in one of the blanks so we could see their relationship build up. We establish that part of Marjorie’s background, which is a little conservative. And Sarah is such a good crier that any chance to get her to cry and to get Julia reacting to the crying is enjoyable. So we broke ‘em up to put them back together. I enjoy them as a couple and I do like a happy Catherine. We wanted somebody to have a happy ending and it goes back to the notion of, they have a happy ending and Selina does not."

Ben Introduces His Wife

"A slightly bossy wife of Asian persuasion after his season of making a few too many Asian jokes, which is psychologically interesting. I think she’s wife number three, so there were two others in there somewhere."

Dan Reminds Viewers That Marjorie Is a Selina Look-alike

In the episode, Dan asks, "Is it weird going hallway to hallway with your mother’s twin?” Explains Mandel, "How often do you get to say "hallway to hallway"? I think we had five different expressions there and that one won out."

Kent Moonlights in Sons of Anarchy

"It seemed crazy and yet so right that there was this other part of Kent. For this quiet sort of numbers guy, there’s a coolness and edge to him that you can never quite put your finger on and you find out he’s in this weekend biker gang and you go, 'Oh, ok.' He seemed like somewhat of a different guy."

Catherine Was Stuck in the Closet During Her Mother's Sexcapade With Tom James

"In the episode, Selina was constantly going after Catherine about her hair. So she had gone into the Green Room to fix her hair, so it’s kind of Selina who caused the whole thing. She hears her mother’s voice and she doesn’t want to see her mother again, and goes into what she thinks is an exit — if you’ve ever been in the real White House, it is a maze of construction — and of course it’s a closet and she gets trapped in there and has a little Blair Witch-y moment."

The Selina-Amy Conversation Is Revealed

"From episode one, Selina was interviewing Candy and Amy says, 'Can I talk to you for a minute?' Now we get to see that conversation. And to see Selina call Amy on her outburst from last season, which I think is something people have been wondering about, now you’re finally getting a chance to see it."

Selina Believes She Has a Political Window

"It’s not something we spend a tremendous amount of time on, but it is true that as a woman she is held to a different standard. Much like how the Obamas can’t hold an official event without someone talking about what Michelle’s wearing or her arms. No one ever worries about what Newt Gingrich looked like in a suit."

Jonah Believes He'll Be President in 20 Years

"God help us all, but at least Richard will be in the Galapagos."

Selina Was Actually Going to Help Elect a Candidate From a Rival Party for Her Own Gains

"The whole vote-switching with Jonah gets overshadowed by the loss, but if you actually think about that: it’s a pretty insane moment that she is trying to arrange the candidate from the other party to win. She would rather Bill O’Brien win so that she can run against him than have Tom James win, and she can’t run against him. Also, she does not want Tom James as president, that does not seem appetizing to her. And that’s an incredible, amazing thing for a candidate to even consider, let alone try and do. Obviously, Jonah screws it all up, but it’s a pretty amazing moment and how shocked Amy is that this is even being considered. It’s selfish on a whole other level and that’s the great thing about Selina, is that we keeping finding new levels of selfishness."

Catherine Is More Like Selina Than Anyone Thinks

"Catherine is Selina’s daughter and a lot of times we go: Catherine is good and the nice one and Selina is the mean one. There are similarities. Catherine has her own aspects of ego and egocentric-ness and the idea that she’s making a film about the tie and ultimately turns it into this thing about her and her girlfriend. There’s a very sort of 'me, me, me, me' thing about that. She misses the shot, she misses that she could have put a lot of clues together about Tom James’ plan that she’s privy to, but never thinks to tell her mother about. She’s very much in her own world, in a world where she’s the most important thing. Even though they seem different, in certain ways, the apple hasn’t fallen too far from the tree."

The Current Date on Veep is January 2017

"Showing the date felt like it would help viewers to follow the documentary so we knew that Congress would get sworn in and vote at the beginning of January and that all this has happened since election day. We needed to set the timeline so viewers knew when we were in present time and when we were flashing back. The finale will pick up the next day, more or less."

Veep airs at 10:30 p.m. ET/PT Sundays on HBO. Make sure to adjust your DVRs for next week's finale, which follows the super-sized finale of Game of Thrones. For all of THR's Veep coverage this season, head here.