Where We Left Off: The Port-to-Port killer infiltrated NCIS and refused to surrender when Gibbs and Vance caught him, so he was shot dead. DiNozzo got a new classified assignment.

What's Next: A new agent is joining the team on a recurring basis; we'll dig into McGee's, Ziva's and Abby's back stories; Diane Neal will return as Agent Abigail Borin; and Scott Wolf will guest star in the season premiere.

Season 9 premieres Tue., Sept. 20, 8PM ET on CBS