The upcoming two-part episode of ABC's Castle is set to feature the return of Dr. Kelly Nieman (Annie Wersching) after she becomes connected to a recent murder.

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"There's a murder that our cops are investigating at the beginning of the episode that seems to connect to her," Castle showrunner David Amann said in a new report by Entertainment Weekly. "That puts us on what we think is going to be a fun, dramatic journey for the audience as we try to solve that murder and figure out what her involvement is in it, if any."

As fans know, Wersching's Dr. Kelly Nieman was first seen in season 6, episode 9, titled Disciple. The plastic surgeon was connected in some way to Jerry Tyson, more famously known as 3XK.

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Amann previously told TVLine that Castle (Nathan Fillion) would likely begin investigating his disappearance again in this two-parter.

However, for now, he will be working to become a private investigator for the 12th District.

"And part of that is driven by his desire to work with Beckett, even though he is no longer officially able to do so. He will follow that to its natural conclusion," Amann told TVLine.

"I think that in light of the fact that he is just starting out as a private investigator, he'll be mainly focused on [his new job]," Amann said when asked about the vanishing storyline.

Castle airs Mondays at 10 p.m. ET/PT on ABC.

Watch the promo for the next episode of Castle here:

Tags: Castle television ABC