'Only Murders in the Building' Season 4 Ending, Explained: Breaking Down Who Killed Sazz

This story includes spoilers for the Only Murders in the Building season 4 finale. As soon as Only Murders in the Building revealed that the fourth season of its true-crime spoof would be a send-up of the film industry, there was only ever one logical choice for who would be the killer. Hulu's hit comedy starring Steve Martin, Martin Short, and Selena Gomez spent its fourth season on a long winding path that followed two sets of celebrity guest-star suspects for the murder of Sazz Pataki (Jane Lynch): the crew behind the fictional Only Murders in the Building: The Movie, and the working-class Westies in the Arconia's West Tower. However, by the final episodes, it became clear that the murder was truly a horrific tale of Hollywood ambition, as the Westies were proven innocent of the murder of Professor Dudenoff (Griffin Dunne).

So, who killed Sazz, and how did our intrepid podcasting trio take the killer down in the OMITB finale? And, more importantly, who's the victim of season 5's upcoming murder mystery? Read on for a breakdown of the ending of Only Murders in the Building season 4.

Who killed Sazz Pataki in the 'Only Murders in the Building' season 4?

In the final moments of OMITB season 4, episode 9, Oliver (Short), Charles (Martin), and Mabel (Gomez) came to the same realization about Sazz's killer, though they weren't together at the time. Oliver and Charles ran into Ron Howard and got the truth behind Project Ronkonkoma (which we'll discuss in a bit), while Mabel was simultaneously helping screenwriter Marshall P. Pope (Pachinko's Jin Ha) with his latest pass at the OMITB movie script. She finally put it all together when she offered the writer a beer out of the unopened case of beer that she brought to the Arconia when she was last seen alive—discovering the missing puzzle piece in an early draft of the Only Murders in the Building movie, penned by Sazz, inside.

The season 4 finale then rounded out the backstory of "Marshall P. Pope," real name Rex Bailey, his connection to Sazz—and what led him to kill her. He grew up the son of a hunter, forced to become a perfect marksman, but he always wanted to be a writer. This father gave him six months, so he went to Hollywood and tried to get a foothold, but no one was biting because "Hollywood is broken." (Or his script sucked.) Then, one day Sazz accidentally ran him over and discovered he had the aptitude to become a stunt performer, and Rex went along with it for the opportunity to be on set.

He eventually got to work on a Ron Howard project and used the opportunity to show one of his screenplays to the legendary filmmaker. The plan went awry though when he tried to get his attention right after a fire stunt, leading him to burn off Howard's eyebrows—and get blacklisted from the stunt world.

In the meantime, Sazz was considering retiring from the stunt industry to become a writer and build a trampoline park in New Jersey. Inspired by Charles and the OMITB podcast, she wrote a screenplay for a film adaptation and did extensive research, or rather, looked into all the plot holes she found in the first season. She even contacted Helga (Alexandra Templer) via ham radio and used the Westies' story as a minor subplot in the screenplay.

By the time Rex ruined his shot at a screenwriting career over the botched fire stunt, Sazz already had a polished draft, and she even showed it to Rex out of solidarity between writers. Rex was instantly jealous of her talents, discouraged her from working on the project further, and stole a copy to pass off as his own. Miraculously, producer Bev Melon (Molly Shannon) picks up the film and fast-tracks it into production, which Sazz finds out about through her stunt industry circles. When she confronts Rex, he's delusional enough to call it "our" movie and shows no remorse or plans to stop it from moving forward.

Sazz is too trusting for this world, so she tells Rex, who's about to make his dream come true off her stolen work, that she's headed to New York to tell Charles the truth about everything. He follows her and uses the info from her Westies subplot to break into Dudenoff's apartment and sniper-shoot Sazz through Charles's window. He shimmies along the ledge to Charles's apartment, watches Sazz's dying moments—her last words are that Charles will avenge her—and throws her body into the incinerator.

As it turns out, the OMITB movie production was largely unsuccessful because Rex couldn't improve the screenplay draft himself. He was a ticking time bomb, either because he wasn't a good writer or person to write that story, or because Sazz was right and Charles, Oliver, and Mabel would eventually figure him out. All in all, Sazz's murder was a case of a failed writer's ambition gone horribly wrong.

Who killed Marshall P. Pope in the 'Only Murders in the Building' season 4 finale?

Once Marshall/Rex/the screenwriter/the killer realizes that the jig is up, he takes Mabel hostage and confesses to killing Sazz, smothering Glen Stubbins (Ben Glenroy's old stunt double played by Paul Rudd, and the only other person who knew Marshall as a stuntman), and accidentally shooting Zach Galifianakis. Though she's being held at gunpoint, Mabel impressively holds him off by dangling the one thing he wants and needs her help with, a successful script rewrite. As she distracts him, Charles and Oliver show a wild amount of bravery by shimmying (or merengue-ing) along the ledge to get to her window. They smartly go to Vince Fish's (Richard Kind) apartment next door to Mabel's, and while Charles and Oliver enter through the window, Vince and Rudy (Kumail Nanjiani)—a.k.a. two of the "cute weirdos who torched a body"—distract Marshall at the front door. Charles and Oliver use Eva Longoria's deadly 19-in-one multi-tool to get Marshall's gun. After several confessions and a bit of multi-tool hijinks, Marshall has the trio held at gunpoint again.

Just when it looks like Marshall's going to kill Charles, Oliver, and Mabel in cold blood, a bullet flies through the window and gets the murderer in the back. Marshall is dead, and the sniper who killed him is... Jan (Amy Ryan)!? If you can recall, the season 1 killer escaped prison in season 4, episode 2, after she stopped hearing from Sazz. It turns out that, instead of going on the lamb, she'd been chilling in Charles's closet and the Arconia's secret passageways for three weeks, waiting for them to solve the murder so she could “exact her revenge” on her lover’s killer. In the end, Jan saves Charles, gets her vengeance, and declares herself and Charles as "endgame" as the cops (sadly no Da'Vine Joy Randolph in sight) take her back to jail.

Do Oliver and Loretta get married in the 'Only Murders in the Building' season 4 finale?

For those of us who have followed every minute of Martin Short and Meryl Streep's rumored romance (which was maybe confirmed by OMITB boss John Hoffman!), Oliver and Loretta's (Streep) engagement in episode 7 was the best subplot of the season. It isn't without conflict; Oliver spends the entire finale consumed by paranoia that Loretta may be the next victim of the main trio's awful luck with deaths left in their wake. But never fear, the season 4 finale does show Oliver and Loretta's courtyard ceremony in full, with Charles and Mabel walking Oliver down the aisle, Oliver's son Will (Ryan Broussard) and Loretta's Dickie (Jeremy Shamos) accompanying her, and Howard (Michael Cyril Creighton) doing the honors for Oliver's beloved pug Winnie.

It's a truly love-filled, beautiful moment, followed by a callback where the wedding reception is soundtracked by merengue after Oliver and Charles did the dance move along the building ledge. However, there's also a bit of tension once the question of Loretta's work comes up again; earlier in the episode, she'd revealed that her show is set to film in New Zealand. Oliver's ready to go with her on a moment's notice, but Loretta points out the tragedy that would be breaking up the podcast crew. As Loretta says, nothing about her and Oliver's romance has been "conventional" and she wants to work out a plan where Oliver can stay in N.Y.C. with Charles and Mabel. Let's pause her for a moment to bask in the romance, friendship, and happiness before the finale's final moments come, and the next body drops.

Who dies in the 'Only Murders in the Building' season 4 finale?

The reveal of the fifth murder in the building doesn't happen until the next morning after Oliver sends Loretta safely off to New Zealand. (Phew!) The trio may have made it through the wedding day without a body, but something sinister happened in the night, as teased by the trickle of bloody water coming out of the Arconia's courtyard fountain. While walking through the remains of the wedding reception, Mabel, Charles, and Oliver spot Lester's body(!) in the fountain. It looks like the doorman (Teddy Coluca) has been dead for hours, or at least long enough for a severe amount of blood to color the water red.

We only saw Lester briefly earlier in the finale, when he took over wedding duties for Oliver. After Oliver notes that all Lester does is "let in murderers," Lester tells Charles that the doorman himself previously got married in the courtyard. "Middle of the night with just the stars and the fountain as our witness. I think it's good luck," he told Charles, foreshadowing his demise, as Charles rushed away from the anecdote (to save Mabel from a hostage situation).

OMITB has shown little of Lester's personal life over four seasons, so the character's backstory is a blank slate for season 5. However, his death will likely have something to do with Nicky "The Neck" Caccimelio, the "Dry Cleaning King of Brooklyn" who was reported missing in the briefest aside in episode 9. Nicky reportedly had ties to the Caputo crime family, and per the OMITB subreddit, there have been low-key "The Neck" references since as far back as season 2. It makes sense, as Nicky's wife Sofia (played by Téa Leoni) says in the season 4 finale, "What happened to Nicky has everything to do with this building." (Sofia also notes that no doorman was on duty when she got to the Arconia.)

We'll have to wait until next year to see what happened on the night of Oliver and Loretta's wedding, and how Charles, Oliver, and Mabel will bring Lester's killer to justice.