CBS's hit police procedural show, NCIS Season 23, is set to return next Tuesday. Titled Knick-Knack, Episode 15 of NCIS Season 23 will release on April 7, 2026, on CBS. You can also catch it later on Paramount+. Previously in NCIS Season 23, we saw the team mourn the loss of Director Leon Vance. However, they were soon plunged into a chaotic case involving the death of a sailor during the Navy Fleet Week celebrations.In the upcoming episode, the NCIS team will investigate a mysterious murder on a museum ship. The case turns even more interesting when a dying Navy captain leaves a clue to a treasure. Can the NCIS team solve the puzzle and find out the treasure that apparently caused the murder? Will they find out the murderer? Here's more about it.NCIS Season 23 Episode 15 release date and streaming details View this post on Instagram Instagram PostNCIS Season 23 Episode 15, titled Knick-Knack, will release on Tuesday, April 7, 2026, on CBS. It will air at 8 PM ET in the US. You can also stream the episode on Paramount+, which offers a variety of subscription plans to choose from.NCIS Season 23 Episode 14: A quick recapEpisode 14 begins with the team mourning the loss of Director Leon Vance. However, the NCIS team soon had to resume investigation when a sailor was found dead in a squad car. Kyle was stabbed in the chest and left to die in the trunk of the stolen squad car. He was seen hanging out with his best friend, Daniel, and a young woman named Annie Carson before he died. Annie told NCIS that she left when Daniel and Kyle began speaking about nukes. Turns out, Kyle had signed up for a Nuclear program, and he was transferred to South Carolina for training. The team later found out that Annie was developing something that could help the authorities keep track of the sailors.The Navy Fleet Week celebrations became chaotic when the NCIS team found out that the sailors were poisoned through their tattoos. Turns out it contained a nanotech that helped to trace their location, too. Unfortunately, the tattoo mobile van owner was found dead as well in the same fashion as Kyle. He was stabbed in the chest. In the end, it was found out that Annie's friend, Samantha, wanted to sell the toxic ink on the black market. She killed the tattoo owner first, and when she was unable to find the ink, she killed Kyle, too, who was leaving the tattoo shop, guessing he had the ink.What to expect from NCIS Season 23 Episode 15?The synopsis of Episode 15 reads (via Rotten Tomatoes):"A murder aboard a museum ship becomes a cryptic treasure hunt when a dying Navy captain leaves a final clue; to solve it, the team must decode what was worth killing -- and dying -- for."In this episode, the NCIS team will investigate a case that involves a mysterious murder on a museum ship that might be tied to a treasure hunt. Can the team find the treasure and the murderer, both? Watch NCIS every Tuesday on CBS at 8 PM ET to find out what happens next.Also Read: NCIS Season 23 Episode 14 recapFollow SoapCentral for more such updates.