Amy Rosoff

Arizona tries to reconcile with Callie, who has big news to share; Teddy faces an important decision; the residents receive new interns; the Chief makes an announcement.

Addison cannot stop thinking of Pete; Violet's ex visits the clinic and Cooper is not happy to see him; Naomi and Sam's daughter secretly seeks Addison's medical advice.

When clues in a murder implicate Castle and Beckett's nemesis, Dr. Kelly Nieman (guest star Annie Wersching), Castle is called in to consult on the case. But as the team delves deeper into the investigation, they uncover connections to notorious serial killer Jerry Tyson.

The BAU is called upon when bioterrorism is suspected in a series of mysterious deaths; Garcia visits her stepbrother to take care of a difficult family issue.

During shooting of a pivotal scene for 'Smokejumpers,' Vince gets contradictory direction from Verner, and Ari and Dana Gordon try to put out the flames. After receiving an unexpected call, Turtle has a clandestine meeting.