When a Marine helicopter is struck by an unknown flying object and crashes in the desert hugging the Marine pilot, Rabb and Bud are sent to investigate the crash. Soon after arriving at the site and finding some unknown metallic-like fragments near the chopper, they are confronted by men in black from the government's Defense Security Division (the DSD). They tell Harm they are now in charge of the investigation and to leave the site. However, Rabb doesn't intend to give up his investigation into this incident so easily.
After being diagnosed with night blindness, Lt. Cmdr. Harmon Rabb, an F-14 Tomcat fighter pilot, is forced to change careers. Cmdr. Rabb chooses to join the Navy's Judge Advocate General (JAG) Corps. There he both defends and sometimes prosecutes Navy and Marine Corps defendants. He is sometimes assisted by fellow lawyer, Lt. Sarah "Mac" MacKenzie, and his other fellow JAG staff.
Many of Rabb's cases require him to both keep up his F-14 qualifications and travel the world, in order to bring justice to the cases he is trying.
Rabb must also deal with the fact that his father, also a former Navy pilot, never returned home after being held prisoner after he was shot down in North Vietnam. Rabb believing his father is still alive continues the search he has pursued to find his father, since his teens.