A detective from Scotland Yard teams up with Castle and Beckett on a murder investigation.
A visit from Adam's (Oliver Hudson) free-spirited mother (guest star Peggy Lipton) puts Jennifer's (Bianca Kajlich) patience to the test and teaches Russell (David Spade) an embarrassing lesson about "art." Meanwhile, Jeff (Patrick Warburton) and Audrey (Megyn Price) find themselves enjoying alternative forms of entertainment as a result an involuntary television deprivation.
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.
