After the passengers and crew of a private plane traveling from New Orleans to Washington D.C. are lethally poisoned, all evidence points to the missing chef, Abby's brother, Luca. Gibbs and the D.C. team work in conjunction with Pride and the New Orleans team to locate Luca and determine why a private tech company was targeted, on the first part of a special two-hour crossover event

When a deep sea diver is murdered on the job, his body and suspected co-workers must remain in a high-tech decompression chamber for four days, leaving the NCIS team to complete an unorthodox investigation from outside the tank.