A prisoner from Leavenworth, Navy SEAL Jack Curtin, who was convicted of killing his wife and a cable repairman she supposedly slept with, has escaped and Gibbs (MARK HARMON), Kate (SASHA ALEXANDER) and Tony (MICHAEL WEATHERLY) are charged with tracking him down and protecting his son – whom they fear he will try to kidnap. While Kate “baby-sits” at the grandparents’ house where the eight-year-old son Kevin is now staying, Gibbs questions Curtin’s former C.O. Commander Foley and orders all of Curtin’s former prison cell belongings be sent to Abby (PAULEY PERRETTE) for clues. Meanwhile, Tony talks to the prosecuting JAG lawyer for more details on his case and Ducky (DAVID McCALLUM) looks at forensic evidence from the trial.
The agents learn that Curtin had served a rough tour in Afghanistan shortly after 9/11 and his disposition was clearly paranoid; still Gibbs can’t piece together why Curtin would have chosen now to escape. Worse, Kate is then fooled when Curtin shows up at the grandparents’ residence; he bounds and gags her, and steals her SIG. In so doing, Curtin is determined to have a few minutes with his son Kevin. When Gibbs and FBI agents fear trouble after Kate doesn’t answer a radio call, they descend on the property, but Curtin manages to flee. Later, Gibbs is able to gain the rattled son’s confidence, who relays that his father is out to prove that he didn’t murder his mother by killing the real culprit.
With that admission, Gibbs changes tactics and directs Tony and Abby to bring in the JAG lawyers so that they can re-investigate the case that put away Curtin. He realizes that Curtin discovered details in the boxes of paperwork confiscated from his cell that pinpointed his wife’s killer. That finding prompted him to escape now and seek vengeance. If Curtin is actually innocent, now the agents need to find him before he truly does commit murder.
Grudgingly, prosecuting attorney Faith Coleman and defense lawyer Diego Clare – now in the private sector – work with the agents. They seem to each have conducted a thorough case, although Curtin continually maintained his innocence. However – poring over the boxes’ voluminous contents -- the agents realize that neither lawyer discovered that Curtin’s wife Margaret was making calls on a disposable cell phone.
While they determine Margaret was routinely calling the C.O. Foley’s house, the calls were being placed while both Curtin and Foley were on duty, so Margaret couldn’t have been having an affair with the C.O. Looking for clues to other men, the detectives talk to Foley’s wife Marie, since the officers’ spouses were understandably often consoling each other during the tour of duty. That questioning doesn’t offer many clues but, upon further inspection, the detectives also learn that – once Foley returned – Margaret’s calls to the house stopped, until Foley had to be hospitalized for a few days. Upon also learning that Margaret had contracted herpes, a condition Marie also had, the agents realize Margaret was actually having an affair with Foley’s wife – who actually committed the murders and whom Curtin is now out to kill.
A step ahead of Curtin, the agents manage to foil his attack when Kate disguises herself as Marie Foley. They halt Curtin, stunned that he would have been satisfied to have this – fortunately aborted --murderous act be a lasting remembrance for his son.