NCIS: Los Angeles Episode 4.10 Free Ride

The NCIS: LA team is sent to covertly investigate the murder of NCIS Special Agent Afloat Jason Niles aboard the USS Van Buren, which is currently en route to Japanese and North Korean waters. As the team begins their investigation, it's clear that something is amiss. The two lead suspects on the ship, a Petty Officer and a Staff Sergeant, both tested positive for cocaine use, though neither admits to using drugs. Deeks finds evidence at the scene of the murder that places the victim in the vicinity of the ships stores, but he's jumped and knocked unconscious by a private contractor. The rest of the team comes to the rescue and arrests the contractor, who is revealed to have been transporting a cocaine and hydrochloride mixture in the paint of the ships refrigerators. The cocaine seeped into the food in the fridge, which is what caused it to appear in the blood of some of the officers, and the private contractor killed Agent Niles before he could report him to the higher authorities.