When a Navy Admiral’s daughter is the prime suspect in a double murder case aboard a research boat, the NCIS team partners with the Coast Guard Investigative Service (CGIS) to work the case. Meanwhile, Lasalle tracks down his estranged brother.

The murder of a Marine provides new clues in the first case Pride and Lasalle ever worked together, just before Hurricane Katrina struck the city and washed away any evidence. Also, the team celebrates Thanksgiving together in Pride’s bar.