Brennan's (Emily Deschanel) life is in grave danger in the upcoming season finale of "Bones."

In "The Nightmare in the Nightmare," CarterMatt reports that the serial killer who goes by the alias "The Puppeteer" is back.

The Jeffersonian team first encountered the psychopath in the episode "The Monster in the Closet," where a social worker's body was found abandoned in a park. The case was not resolved. Brennan and Booth (David Boreanaz) never got to follow up on what happened when they retired.

This time around, the killer is targeting someone closer to home. For a while now, the object of his attention has become Brennan.

The promo reveals that Booth and Aubrey (John Boyd) will be able to find the culprit's lair. They know it is The Puppeteer because of all the marionettes strewn all over the place.

Booth, however, quickly finds something terrifying. The clothes of one of the puppets belong to his wife. He deduces that Brennan is the target and hastens to warn her.

Unfortunately, his warning will come too late, as the killer has already abducted her. In the clip, Booth is slowly losing his patience with his colleagues, knowing that his wife is in danger.

For Brennan, the case has become personal. She feels guilty that her time off from the Jeffersonian allowed such a monster to be at large. She thinks that if she and Booth had not taken a leave of absence, the killer could have been behind bars by now.

What she does not realize is that she has now become the target. The murder wants her to be the next marionette in his collection. Brennan will have to stop him at all cost, or at least until help arrives. Will Booth and the others get to her in time?

"Bones" season 11 airs on Thursdays at 8 p.m. EST on FOX.