Linden and Holder, moments after figuring out that the Nicole/Ames meeting that led to Rosie's murder was also attended by somebody from the Richmond campaign, are very nearly arrested before a last-minute "enemy of my enemy" deal puts them in cahoots with the Mayor's people. Turns out those magic bones were part of some kind of escalating prank war that ultimately led to the faked photo from Season One, or something, but whatever: The campaign and its folks are the main target of the investigation once again.
How Linden and Holder do detective work throughout this episode is, they sit around in their car and make up wild theories and then act as if their wild theories are correct, and eventually -- because the show is like this -- they turn out to be correct. So they get Roberta to admit that Chief Nicole is an abusive lover and breaker-of-bones, and eventually twist her around into giving them this elevator footage that supposedly didn't exist, which shows who the person is. (Also, it sounds like Roberta wasn't the one that put up the haunted-tree picture, but whatever. I have a theory about that.*)
But first, there's a lot of hilarious red-herring stuff where first you think it's Jamie, then Gwen, then Jamie, then Gwen, then Holder and Linden split up and one of them thinks it's Jamie, and the other one thinks it's Gwen, but then they decide no, it's Gwen and the other thinks it's Jamie, and then they get back together and it's like, "You got your Gwen theory in my Jamie theory! You got your Jamie theory in my Gwen theory!" Forever.
Meanwhile, Mitch is finally back and spreading her motherfucking cheer all over the place. She and Terry have a competition to see who is more of a bitch. Terry wins. Then Mitch and Stan have a competition to see who is the biggest asshole, and Mitch wins that one by a mile. Which just goes to prove what an asshole she is, because she hasn't even killed any people for no reason, which Stan has done dozens of times at this point. Then she and Tommy have a competition to see who's less worthy of forgiveness, or love. That one is a draw.
But just as we're about to find out who will be the new Mayor, Darren gets a call from this crazy-sounding grizzled old prospector from the Gold Rush, who tells him he has a secret to tell Darren. Who the man is, is Ted Wright: The only subject Darren ever makes a speech about, every day, as he goes around making speeches that are just about this one guy. And what his secret is, besides being a boxcar-riding hobo from the Olden Days, is that his grandson Jamie? Has been lying about some shit. Like how he was on the 10th Floor of the Wapi Casino the night Rosie Larsen died. Oh, Jamie. And you were rockin' that sweater vest tonight, too.
week: Rosie's killer is revealed! I totally bet you it's Jamie. That's probably what's going to happen. Or Rosie will be looking at a blade of grass or a crayon, like in Electric Company and it will zoom and blur and then suddenly *it's all happening in her very fertile imagination, because Rosie never died, she just has autism.