Spoiler Alert: This article contains spoilers for Season 1 of Only Murders in the Building.
While the main mystery on the first season of Only Murders in the Building is identifying who killed Tim Kono (Julian Cihi) during a building-wide fire alarm incident, there's another long-standing question about who actually pushed Zoe (Olivia Reis) off of the Arconia's roof.
The teen, who was a member of The Hardy Boys alongside Tim, Mabel Mora (Selena Gomez), and her boyfriend, Oscar (Aaron Dominguez), fell to her death during a New Year's Eve celebration about a decade before the events in the Hulu original.
Though her boyfriend, Oscar, was framed for the killing and he spent years behind bars, viewers learned the identity of the actual killer in the seventh episode, "The Boy from 6B."
Who really killed Zoe in 'Only Murders in the Building'?
As Mabel, Charles-Haden Savage (Steve Martin), and Oliver Putnam (Martin Short) investigate Tim's murder for their own interests and for the sake of their podcast (which shares the same title as the show), they discover that the businessman had made many enemies leading up to his brutal death — including Oscar.
In the first few episodes of the comedy, viewers slowly learn details about Zoe's mysterious demise. While we are initially led to believe that Oscar is the one who pushed her off the roof, a new culprit is revealed "The Boy from 6B."
The seventh episode, which features very little verbal dialogue, is largely told from the perspective of Theo Dimas (James Caverly). Theo, who is deaf, is the son of Arconia resident Teddy Dimas (Nathan Lane). The famous deli owner is also the main sponsor for the Only Murders in the Building podcast.
The episode features scenes from the present, which reveal that Theo is a grave robber, and moments from the past, from when he was a teenager.
In the flashback scenes, The Hardy Boys snoop on Teddy and Theo's apartment on New Year's Eve while the latter relative hides in a secret room. Zoe steals an emerald ring from the residence, and she expresses to her friends that she finds Theo to be attractive.
Later on, when many of the Arconia residents are on the roof to celebrate, Theo and Zoe have a conversation alone in sign language. They hint that they've had a secret romantic relationship, but things soon sour when Theo asks Zoe to return the emerald ring.
Zoe decides to give it back, and she notes that it doesn't matter because it's not an engagement ring. Theo responds by saying that he'll get her a real ring some day, if she wants it. Zoe starts to laugh, but she soon apologizes for being mean.
As she takes the ring off, she admits that she pities Theo. When she hands it to Theo, she begins to push him. The two start shoving one another, and Theo seemingly accidentally pushes Zoe off the roof.
Tim does witness the altercation, but Theo's dad makes him swear to secrecy. Because Tim does choose to stay silent, Oscar is arrested for the crime. After all, witnesses had heard him arguing with his girlfriend just moments before her death, while nobody heard or saw Zoe with Theo (except for Tim).
Did Theo also kill Tim Kono?
The seventh episode concludes with Theo texting his dad about how the three podcast hosts were onto them. He also throws Mabel and Oliver into the back of his grave robbing van. Though it seems like Theo is a likely candidate to be Tim's killer, viewers eventually learn of his airtight alibi in the following episode, "Fan Fiction."
In the last few minutes of the eighth episode, Detective Williams (Da'Vine Joe Randolph) calls to tell Oliver that Tim was actually poisoned before he was shot. The Dimases weren't in the Arconia when the fire alarm went off, so they could not have been responsible for his death.
With only a few episodes left in Season 1 questions still remain about who harmed Tim Kono — but it wasn't Theo or Teddy.
New episodes of Only Murders in the Building debut on Tuesdays on Hulu.