Upton brings SVU detective Petrovic back into the fold to help with the investigation of a tender-age kidnapping.
Deputy Director Ochoa tasks the team with a covert operation focused on dismantling a terrorist group. Callen worries about what the assignment means for the future of the team.
Castle is asked to consult on a case when evidence in a young woman's murder implicates Dr. Kelly Neiman (Annie Wersching) -- Castle and Beckett's nemesis.
As Agent Carter gets closer to Stark's stolen technology, her secret mission could be unraveled by an SSR arrest.
Molly decides to go after a big career move and asks Mike to accompany her to a staff party; Mike hates Halloween and doesn't like the idea of mingling with other teachers, but Molly convinces him to go.