Hulu’s Only Murders in the Building episode 4 sets up a potentially dark ending for the series, thanks to a twist involving Tina Fey’s character. The murder mystery centers around three strangers (played by Steve Martin, Martin Short, and Selena Gomez) that live in the fictional Arconia building and share an obsession with true crime. Soon after bonding over their love of a popular podcast, the trio unexpectedly finds themselves investigating the murder of Tim Kono (Julian Cihi).

It’s revealed in the premiere episode that Gomez’s character, Mabel Mora, had a close connection to Tim. The two grew up together, spending a lot of time in the Arconia as children and teenagers, before drifting apart. It’s unclear why Mabel decides to hide this fact from Charles (Steve Martin) and Oliver (Martin Short). It’s possible that she doesn’t want to arouse their suspicions, considering that she’s seen having a nasty argument with Tim in a flashback. However, it did appear as though Mabel’s history with Tim would be one of the main unresolved questions of Only Murders in the Building. But episode 4, “The Sting”, offers an arguably bigger surprise.

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The episode sees Charles, Mabel, and Oliver seek out the help of Cinda Canning (Fey), a Peabody-winning podcast host. At the end of “The Sting”, in a flashforward, it’s revealed that Cinda is making a podcast that focuses on Mabel, Charles, Oliver as her primary subjects instead of Tim. Fey’s character clearly takes a fair amount of inspiration, both in her name and career trajectory, from Sarah Koenig. Koenig is the host of the Serial podcast, which focused on the case of Adnan Syed in its game-changing first season. And, similarly to Koenig, Cinda’s specialty is her ability to delve into the unresolved realm of true crime. This strongly suggests that, whatever happens to the trio of protagonists, it won’t be resolved by the season’s end. It’s also possible that even if they uncover the truth of what happened to Tim Kono, it will lead them down a path of even more questions.

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This possibility is bolstered by the opening scene of Only Murders in the Building, a flashforward showing Charles and Oliver running out of The Arconia as a SWAT team swarms the building. However, after developing a bond with Mabel, Charles and Oliver rush back to look for her. When they find her, Mabel is covered in blood. She’s quick to defend herself, saying the sketchy situation isn’t what it seems. Speaking with E! Online, series co-creator John Hoffman affirmed the importance of episode 4’s flashforward, noting: “Cinda Canning is the one who holds the tease.”

It’s true that Only Murders in the Building is a comedy, starring two comedy legends in Martin and Short, but the show hasn’t been afraid to dwell on the emotional costs of what its protagonists are involved in. Charles latches on to Tim’s murder to alleviate his loneliness and boredom. And for Oliver, a financially struggling Broadway director, he hopes to turn the case into a true-crime hit. Mabel is the most involved, as she’s driven to find out what happens to her former friend even if it comes at the cost of her own safety. Given these stakes, the finale of the Hulu mystery could pack an emotional punch that leaves the door open for season 2.

Next: Only Murders In The Building: How Many Episodes There Are (And When The Finale Is)