NCIS uncovers a bomb plot and a long-running theft ring while investigating a death at a Quantico reunion. Meanwhile, Torres and Quinn adjust to life on Gibbs' team, including new seating arrangements in the squad room.
Gibbs sends Bishop and Quinn to Philadelphia to work with MI-6 Officer Clayton Reeves on the murder case of a British operative. Meanwhile, Quinn deals with the NCIS case that caused her to leave the field.
Bishop questions her previous work at the NSA when she's sent to Gitmo to collect evidence for a Navy chaplain murder case. In the meantime, her brothers visit for Thanksgiving and want to know from her co-workers who she's dating.