LMP
Blue Crack Supplier
This past episode was all kinds of bizarre, and while hilarious (particularly the Dean, clearly the MVP here) and well executed (barring perhaps the twist at the end, just because it's out of place in this particular episode) it feels a bit early for them to go concept episode given all the heavy lifting they set up with the first two episodes and what the end of this one sets up for next week.
I was a bit mystified at first, thinking I was overthinking the David Fincher-ness of it all but, but it became clear pretty early. Granted, serial killer films are clearly the "genre" here, but the bulk of it is Fincher and I have a feeling that more than any other parody they've ever done stuff went over the audience's head, including many of their crazy cult level fans.
The set up is clearly Zodiac (the "killer" gleefully writing to the authorities, the detectives becoming obsessed with an ultimately unsolvable case, Annie realizing she's talking to a likely suspect once she's already alone with him, etc.) but there are a lot of other direct references to Fincher's work (down to Shirley's kids singing a version of Radiohead's "Creep" that's very similar to the one that scored the teaser trailer for The Social Network) including Seven. The fact that it's raining all the damn time, doing library research while playing the same Bach piece that Morgan Freeman's character did, the chase scene with Star Burns at the end, there's a lot of Seven in it.
It's a bit convoluted though, first off Zodiac, while an incredible film, was a flop and isn't all that highly seen, so hinging the whole thing on that as a parody was interesting when Fincher has a more recent and widely known serial killer mystery in The Girl with the Dragon Tattoo that's more widely seen and not really referenced here; but also it throws in a lot of other references to other serial killer things like Red Dragon (the opening credits mirror Red Dragon's) and the tv version of Hannibal is referenced with the antlers in the stable scene, and when Abed goes on his rant about mildly autistic detectives on broadcast and cable tv (and then proceeded to delete episodes of Hannibal and The Bridge from his DVR).
It's a Fincheresque hodge-podge of that whole sub-genre. No need to think it all has to be one focused parody.