With Gibbs retired and boat-building in Mexico, the NCIS team must learn to work without him. As each team member deals with the absence of Gibbs in their own way, Ziva's past comes back to haunt her when she inadvertently witnesses an assassination of a military attache by her former Mossad partner. Convinced her father ordered the hit, Ziva seeks refuge at the Israeli Embassy. As the NCIS team, now headed by Tony, works to prove her innocence, Ziva reaches out to the one person she has always been able to trust.