Harm & Bud are sent to Twenty-nine Palms Marine Base to investigate the mid-air collision of 2 helicopters & subsequent crash of one helicopter which killed the pilot.

Upon arrival at the crash site, they learn that the ""other"" aircraft was not another helicopter as was first thought. A piece of wreckage that is found that belongs to the ""other"" aircraft only deepens the mystery. When members of the Defense Security Division appear onscene with orders to take over the investigation and crash site, Harm becomes convinced that a major cover-up is in the works.

The base commander, Col. Barrett gives Harm time to investigate further. When Harm & Bud are out driving the base at night, they see an unknown type aircraft flying above them and follows it, but are soon blocked by a fence over the road marking the property of the ""Bradenhurst Corporation"".

Clark Palmer, a renegade government agent, breaks into Harm's apartment and incapacitates him. Palmer then makes a cast of Harm's face in order to prepare a mask that he can wear to pass for Harm. Palmer plans to murder the key witness in the trial at which Harm and Mac are currently prosecutors.

When Harm doesn't show up for the start of the trial, Mac takes his place, leaving Bud to search for the missing JAG lawyer. When Bud finds Harm trapped in an ingeniously booby-trapped apartment, the two must find a way to escape before the assassin can carry out his plan.

When Harm and Mac set out to find C.I.A. Agent Clayton Webb's killer after his body is found aboard a burning ship, they inadvertently uncover a rogue government spy agency.

Retracing Webb's steps, Harm and Mac learn that he was on a top-secret mission to deliver a high-tech weapons project to the proper authorities when he was stopped. Waiting for Harm and Mac when they discover this, though, is none other than Harm's former nemesis, ex-C.I.A. Agent Clark Palmer, now working with the rogue spy agency, who will stop at nothing -- including Harm's murder -- to get his hands on the top-secret project.

Harm fears he's losing his mind when he begins to see and hear his deceased father. Worried that he may be going insane, Harm finally confers with his Navy psychiatrist girlfriend who tells him she's treating a Marine officer with similar symptoms and suggests that Harm isn't experiencing anything unusual for someone who's lost a loved one under stressful circumstances. But before Harm can come to terms with the visitations, he begins to suspect that there's something more sinister involved that could cost him more than just his sanity.

Harm faces a court-martial when a letter critical of the President appears on the Op-Ed page of a newspaper and is traced to his computer.

As an investigation threatens Harm's promotion as well as his entire career, a well-known conservative organization offers to represent him and Harm accepts. The key to Harm's defense is to find the actual letter-writer, so Bud digs through Harm's old case files searching for those with an axe to grind.

On Christmas Eve, Harm pays his annual visit to the Vietnam Memorial to honor his father who was shot down on Christmas Eve, 1969. At the memorial, Harm meets a beautiful, but mysterious woman, who claims to have known Harm, Sr. She used to be a singer in a traveling USO tour and she met Harm's father shortly before his fateful flight.

In an unusual casting twist, Harm stars as his father in this episode, and many familiar faces show up playing different roles.

A Marine sergeant in prison needs Harm's help again when his prints are found on a murder weapon.