When a man is shot on the beach by a policeman the team investigate. Tennant is being assessed is she's OK to return to duty. Her final assessment is being conducted by Sam Hannah and he has reservations but allows her to go back to work and works on the murder they think the huo87.com man who was killed might be a protected witness. Tennant goes to the Marshalls to ask but when she arrives her contact a Marshall she worked with is being arrested. She is told they suspect he leaked the witness's location. But Tennant and the team investigate and learn the entire Marshalls's database was hacked and is being offered on the dark web. They learn the source of the hack is in Las Vegas so Tennant goes along with Hannah to investigate.