The daughter of high-powered diplomats, Special Agent Emily Prentiss joins the team and must convince Gideon and Hotch she deserves the job.
Veronica infiltrates a commune-like cult to find out what happened to a former popular student who had a drastic personality change after joining the group.
Ziva has a tense reunion with her father, the head of Mossad; Gibbs is forced to make a shocking decision.
In order to help a wounded reservist, the team tries to expose the truth about a security firm.
During an interrogation at the witness stand, a prosecutor has what he thinks is a heart attack; Wilson is determined to prove that House is hiding something; Park starts to come out of her shell.