How Jan and Her Bassoon Fit Into the 'Only Murders in the Building' Finale

Spoiler Alert: This article contains significant spoilers for Season 1 of Only Murders in the Building.

After weeks of twists and turns and more than a few red herrings thanks to the investigatory tangents that Oliver Putnam (Martin Short), Mabel Mora (Selena Gomez), and Charles-Haden Savage (Steve Martin) went on, Season 1 of Only Murders in the Building has officially concluded. The podcasting trio, the rest of the Arconia residents, and viewers now officially know who poisoned and shot Tim Kono (Julian Cihi) on the Hulu series.

The tenth episode, "Open and Shut," revealed that Charles' new girlfriend, Jan (Amy Ryan) killed the businessman after he called off their romance.

Though Jan was a prime suspect for several episodes, the Season 1 conclusion still managed to deliver a few surprises — and the final moments also set up the premise for Season 2.

Why did Jan kill Tim Kono? Read on to find out her motive, and for the finale recap.

In the opening minutes of the tenth episode, Mabel and Oliver confront Charles about their recent discovery that Jan and Tim were lovers. They note that Tim had been throwing out cocktail glasses and suicide notes on the sixth floor, which is where Jan lives, shortly before his death.

Charles, who is dealing with a considerable nose bleed, doesn't believe his fellow podcast hosts. He goes back to his apartment, and Jan later visits him to explain why she lied about being a first chair bassoonist.

She explains that she's never taken rejection well, and she acknowledges that the bassoon cleaner found in Tim's apartment is hers.

Charles and Jan reconcile after admitting that they are falling for one another. Jan offers to make Charles a cocktail, and he appears to drink it while he's continuing to pat his nose bleed with a handkerchief.

As Jan and Charles chat, the Brazzos actor admits that he would still love Jan even if she had murdered Tim.

Charles says that he figured out Jan was the killer because the "J's" in her own handwritten notes matched the ones found on Tim's suicide note. She confirms that she stabbed herself to make it seem like she was a target of the real killer.

He then says he's been taking "stage sips" of the cocktail because he believes Jan has poisoned it. Unfortunately for Charles, Jan switched things up, and she placed poison in his handkerchief instead.

Jan admits to the affair with the decedent, and she explains that she was drawn to him in the same way she was drawn to Charles.

"Hello! I'm a sucker for lonely guys with notable age differences I meet on elevators. I think you know that," Jan says.

She then confesses to killing Tim while Charles begins to lose control of his motor skills.

Two days after Tim broke up with Jan, she lured him to her apartment by offering him an Old Fashioned.

Once they were done drinking, Jan gave him a garbage bag with the glasses to throw out. She played a recording of the bassoon so her neighbors would think she was performing live during the time of the murder (and, thus, supplying her with an alibi).

After Tim began to feel the effects of the poison, Jan went to his apartment and she shot him. She staged the scene to look like a suicide. Her main motive to kill Tim was the fact that he made her feel like a second option.

Jan was upset that he rejected her, and she suspected that he was seeing someone else because he had bought the emerald ring.

"You know how I feel about being made second," Jan tells Charles. "That's a big trigger for me."

After she's done explaining herself, Jan leaves Charles' apartment to deal with another matter entirely: she needs to kill all of the Arconia residents who may suspect her because of the podcast.

Though Jan ultimately tries to burn down the Arconia by sneaking gas into the apartments (which all, once again, have newly-functioning fireplaces) Mabel and Oliver are able to thwart her plans just in time.

She is arrested in the final moments of the finale. Though the Only Murders in the Building hosts try to celebrate the closing of the case and the success of their podcast, another resident is soon killed.

The opening moments of the series did show Mabel covered in blood while leaning over a dead body, but viewers didn't find out the identity of the next victim until the end of "Open and Shut."

The Acronia's nosy super, Bunny (Jayne Houdyshell), is the unfortunate victim. She died in Mabel's apartment shortly after the twenty-something was heard saying that Bunny was both a "cranky, old b---h" and the "most hated person in the building."

To make matters worse for the podcast host, Bunny was stabbed to death with one of Mabel's knitting needles.

All 10 episodes of Only Murders in the Building Season 1 are available to stream on Hulu now.