Credit: Richard Cartwright/ABC Photo: Castle Gestures to Ryan in Castle Season 6, Episode 3: “Need to Know”

Say it ain’t so!

Granted, Castle (Nathan Fillion) doesn’t technically work for the NYPD, but with his fiancée Beckett (Stana Katic) in D.C. at least for the foreseeable future, could he be shadowing another detective in her place? We suppose we shouldn’t be surprised that a new detective is joining the 12th precinct to replace Kate Beckett, but is this newbie really Castle’s partner?

The official ABC synopsis for Season 6, Episode 3: “Need to Know” is mostly about the murder of a Saved By the Bell-esque star but a little tidbit at the end confirms that a new detective is bound for the 12th.

Check out the synopsis in its entirety below:

With Beckett still in D.C., Castle and the boys investigate the murder of former child star Charlie Reynolds, who rose to fame playing the lovable nerd on an early 90s High School sitcom. But the case takes a turn for the strange when Agents Beckett and McCord arrive from Washington to take over the investigation, creating competitive tension in the precinct. But why would a washed-up actor's death warrant Federal scrutiny? Whatever the reason, Beckett and McCord aren't telling. Meanwhile, Castle has to contend with a new face at the 12th, NYPD Detective Frank "Sully" Sullivan (Joshua Bitton). Antonio Sabato, Jr. guest stars as Ramon Russo, the victim's former sitcom costar.

The synopsis doesn’t confirm that Sully is Castle’s new partner, but either way it sounds like the mystery writer’s feathers will be ruffled by this new face.

Do you think Castle needs a new detective to shadow? Vote below!

Castle Season 6, Episode 3: “Need to Know” airs on October 7 at 10 p.m. ET on ABC.