"Epitaph One," the fabled 13th-episode-that-was-really-a-14th-episode season finale to the first season of "Dollhouse," screened a few days in advance of its DVD debut Friday to a crowd that filled literally every seat in the huge Ballroom 20. The crowd, of course, was predisposed to like the episode, but they were not let down. "Epitaph One" is a bold, terrifically ambitious piece of television, and the audience ate up every minute of it (one unexpected act break led to several rounds of sustained applause). Because there's basically no way to discuss the event without delving into some spoilers (and the less you know, the better), this piece will be spoiler-heavy, though I'll warn you before the going gets rough.

The screening opened with a short speech from "Dollhouse" creator and all around geek titan, Joss Whedon, who thanked his fans for their passion, which he credited with keeping "Dollhouse" on the air. He talked briefly about some of the other projects he has up and running, including the forthcoming film "Cabin in the Woods" (which he maintained his customary silence about) and the "Buffy the Vampire Slayer" comic book, which will soon see its Whedon-scripted eighth-season finale. But while Whedon would get plenty of time to hold court later on in the day, the screening was all about letting fans see the "lost" episode, which got caught in a licensing battle between Fox the studio and Fox the network. And if you are going to keep reading, there will be spoilers.

Very briefly, "Dollhouse" caused the most concern among critical types and people with blogs (and the Venn diagram intersection of the two) because of a number of issues, most of which boiled down to, "Does Joss Whedon know where he's going with this?" Before "Epitaph One," the show had dropped intriguing hints that it had a rough idea of what lay in the future. After "Epitaph One," it's hard to say that Whedon doesn't have a very concrete plan for what to do with these characters and where to go with them. Does Whedon have a plan for the sometimes morally troublesome staff of the titular brothel/extreme adventure vacation travel agency? Yes. Does he have a guiding purpose in mind for the show's plot and themes? Yes. And is he ever going to figure out what to do with Eliza Dushku? Signs point to yes.

"Epitaph One" means that title about as literally as it can. It takes place in a post-apocalyptic Los Angeles in the year 2019, a world where a very few have not had their minds and identities decimated by the technology that allows the Dollhouse to swap identities into people like they're so many external hard drives. The episode is non-specific on how this has happened, but it's led to a world where a handful of people with pure identities are on the run from faceless hordes, presumably with identities julienned all to hell. Among others, these include Mac (the winning Felicia Day, giving good Armageddon waif) and her band of rebels, which includes another young woman, two young men, a middle-aged guy and a young girl who seems to be the older guy's daughter. (The speakers made it hard to pick out all of their names, so I'll go for ambiguity rather than horribly messing things up.) After racing from the hordes out to get them, Mac and company happen upon the Dollhouse, and that's when the episode begins to dart between past, present and future, filling in gaps in the "Dollhouse" chronology (like how Topher came to work there) and suggesting turns the story will take in the future. To say any more would be telling too much, but the episode is one of the most ambitious pieces of storytelling Whedon has ever been involved with (he didn't write the teleplay, which is credited to Jed Whedon and Maurissa Tancharoen, but is credited with the story), and it ends on an absolutely stunning image.

The best thing about "Epitaph One" is how easily it crystallizes what Whedon is trying to get at with "Dollhouse" and how nicely it lays out not only where he's going with the show but where his whole career has been leading to this point. The series has always been a rumination on identity, sure, but that rumination felt decidedly low stakes for too long because we never quite saw just how monstrous such technology would be on a grand scale. "Epitaph One" gives us a taste of that and then some, suggesting that we are our memories, our feelings. If we don't have those, then we may as well just be a big series of interchangeable parts.

"Epitaph One" also humanizes the various, personality-less dolls and the Dollhouse staff over the course of its length, suggesting that they all do have moral codes, that they have things they will refuse to do or be when push comes to shove and that the price exacted for this will be very dear indeed. When Whedon cast Olivia Williams as Adelle DeWitt, head of the Dollhouse, it seemed like she'd get to play the sorts of moral grays she plays here more often than she did in the first season, but she's got a long number of killer scenes here, where you can feel the weight of every decision she's made.

"Epitaph One" also excites because of how terrific it looks for something like half the normal budget of a "Dollhouse" season one episode. Director David Solomon uses tightly held frames and a roving camera to suggest the peril the world has come to with a minimum of set dressing and props (only in the very finale do we get a sense of the sweep of how bad things have gotten). "Epitaph One" suggests far more than it shows, and that makes it all the better.

The best thing about "Epitaph One," though, is the way it lays out building blocks for where the series will go. The hints it offers of what's to come are sketchy, at best, and Whedon suggested that not all of them should be taken at face value, but they create the sense of something epic that we're only seeing the tip of, that there is a bulk and a weight to this show that could outdo anything else Whedon has done. It's a terrific piece of television, and it should be even in the comfort of your own home, rather than being seen surrounded by thousands of screaming fans.