Only Murders in the Building season 2 finale review: Charles, Mabel and Oliver host a killer reveal party

NOTE: This post contains spoilers for Only Murders in the Building season 2 episode 10, "I Know Who Did It." Read our previous Only Murders in the Building season 2 episode 9 right here.

The moment when the killer is unmasked is a whodunnit staple and the Only Murders in the Building season 2 finale does not disappoint. There are fakeouts, twists and a cliffhanger that announces a murder outside of the Arconia. After last week’s Becky Butler bombshell, "I Know Who Did It" is a satisfying end to the case of who killed Bunny Folger (Jayne Houdyshell).

In narration and flashbacks, Poppy (Adina Verson) reveals her journey from Oklahoma to New York City. Turns out it was not the work of Cinda Canning (Tina Fey), as the award-winning podcaster is in the dark about her assistants’ identity, which speaks to how unobservant Cinda is. One element that stretches some credibility is Poppy put up with years of being treated like crap, even though she had the power to bring Cinda’s empire down. Blackmail was an option; instead, Poppy tried to use her position to get a promotion with her idol.

After revealing to Mabel (Selena Gomez) that she is Becky, Poppy meets with her, Charles (Steve Martin) and Oliver (Martin Short) at the Pickle Diner, telling the team about some of Cinda’s more unusual phobias (slow motion and tomatoes), leading to one of the funniest sequences during the killer reveal party.

Gathering almost every major season 2 player in Bunny’s apartment under the guise of the killer reveal party — the ongoing joke about this phrasing is very funny — to broadcast on Instagram Live mixes the familiar format with a contemporary spin. Unlike last season’s showdown with Jan (Amy Ryan), this plan is meticulous and everyone in the room (Becky aside) is in on it. "It’s all theater," Charles dramatically announces. 

It has been a while, but Oliver is far from rusty directing a new cast of actors even if this show is not for the stage, from Lester’s (Teddy Coluca) impressive acting experience credentials and Tracy Letts namedrop (another laugh-out-loud moment) to Howard's (Michael Cyril Cerighton) failed audition for Joseph and the Technicolor Dreamcoat. 

The group makes Cinda squirm by pulling out their best slow-motion acting and Charles is quick to use her tomato phobia against their rival to try and elicit a confession before Mabel says that the killer is Alice (Cara Delevingne), who stabs Charles after she is outed.

This reveal is too neat and there is no way they are killing off Charles, but everyone is compelling in their reactions. Alice didn’t kill Bunny for the Rose Cooper painting (the art collective subplot is a red herring that remains lackluster). However, Bunny’s painting is part of the overall motive.

Cinda says that she is impressed by Mabel and offers her former rival a podcast. If steam could come out of Poppy's ears it would, as her anger finally bubbles to the surface.

Poppy was the one who originally brought the Rose Cooper mystery to Cinda for their next podcast idea, only to be belittled. It isn’t until Bunny’s murder that Cinda sees any value and refrains from making a fart joke. Then, she sneezes to the presence of Bunny's parrot, Mrs. Gambolini, confirming that she has an allergy to the bird. Charles then pops up from playing dead as they confirm that Poppy is the murderer.

How did Mabel figure out it was Poppy? Earlier when Detective Williams (Da’Vine Joy Randolph) rang to tell her that none of her DNA was on the knife, but instead they found a dead girl's DNA, it all clicks into place. Mabel realizes that "Savage 14" was actually "Sandwich 14," aka Poppy’s unappealing liverwurst and marmalade lunch order. 

The reveal within the reveal is very fun and the final piece of the puzzle is that Detective Kreps (Michael Rapaport) was talking about Poppy and not Cinda in episode 9. He is arrested alongside his girlfriend. It was two killers, after all. Poppy texted the trio to get out but didn’t factor in Mabel returning to her apartment and ruining the plan to frame them. Mabel was right to think there were loose ends, but this finale wraps everything up.

But, wait! There is still more episode, including a sweet, emotional scene in which Oliver tells Will (Ryan Broussard) the truth about the DNA results. Will seemed off last week because he knows his dad’s tells, so he realized he was lying. "If you’re not my father, then I don’t know what a father is," Will tells him; that cozy patented Only Murders vibe continues. 

In other good news, Oliver is offered a Broadway directing job and Charles has been so popular on Brazzos that his dementia is in remission (yeah, you read that right). He awkwardly asks Joy (Andrea Martin) out on a date and Mabel also makes steps to move forward — though not with Alice.

Flashing forward to a year in the future propels the series ahead to the opening of Oliver’s new Broadway show. It has been one year without a murder, but Mabel should be careful about what she says. 

In great stunt casting, Paul Rudd plays Ben Glenroy and stars opposite Charles in Oliver’s new play. Charles warns Ben to "stay away from her" because he knows what Ben did. This is the first part of the mystery that turns deadly when Ben collapses and dies during the opening scene. A bloody mouth suggests poison. 

"You’ve got to be f***ing kidding me," says a glammed-up Mabel about the twist and another Only Murders in the Building killer cliffhanger. 

All episodes of Only Murders in the Building season 2 are now available to watch on Hulu and Disney Plus.