Fatima is concerned about Rountree's state of mind after the police stop. Sam is planning to sell his boat to buy a house so his father, suffering from Alzheimer's, can move in with him. Kilbride tells Callen his FOI request from the Drona Project has been denied. He also informs Callen that Katya's deep fakes of him have been targeted. Instead, Kilbride gives Callen the day to meet with Nate, who has been in contact with Hetty. Marine Master Sgt. Boomer Hayes, a military working dog, has been abducted from Mary Smith's house. Smith thinks her ex-boyfriend, Dennis Adams, took Boomer. Although a jerk, Adams isn't much of a suspect. Sam suspects that a criminal may have taken Boomer. Sam's dad calls him, lost, after escaping from his caretaker. Nate admits Kilbride wants him to assess Callen. Shyla finds a bounty for Boomer on the dark web. Fatima locates surveillance of a man pushing a shopping cart who may have taken Boomer. Rountree's canvas gains surveillance of a man loading a bagged Boomer into a vehicle. Kensi, Fatima, and Rountree seek Joseph Jones, identified as the man who took Boomer. Kensi goes in alone as Fatima and Rountree are stopped by a locked gate. When Jones attacks Kensi with a welding torch, Fatima picks the lock and chokes Jones unconscious with an air hose. But Boomer isn't there. Kensi uploads Jones's car GPS. The prints on Jones' money are from Brian "Buster" Miller, who has a history of dog fighting. Nate proposes repressed-memory therapy for Callen. Fatima suggests both Rountree and his sister should see therapists. Kensi stages a car accident to draw out two of Nick Reed's gang while Fatima and Rountree take down two more. They locate Boomer among the dogs held there. Kensi returns him to Mary.