Following in his father's footsteps as a Naval Aviator, Lieutenant Commander Harmon Rabb, Jr. suffered a crash while landing his Tomcat on a storm-tossed carrier at sea.

Diagnosed with night-blindness, Harm transferred to the Navy's Judge Advocate General Corps, which investigates, defends, and prosecutes the law of the sea.

[note 1] There, with fellow JAG lawyer Major Sarah MacKenzie, he now fights in and out of the courtroom, with the same daring and tenacity that made him a top gun in the air.

- 2nd and 3rd season opening narration, read by Don LaFontaine Lieutenant Commander Harmon "Harm" Rabb, Jr. (David James Elliott), a former aviator, and Marine Major Sarah "Mac" MacKenzie (Catherine Bell) work for the Headquarters of the Judge Advocate General, the internal law firm of the Department of the Navy.

Despite an initial reluctance to co-operate from the United States Department of the Navy (due to sensitivity in light of all the accumulative negative publicity that had been generated from the Tailhook scandal and its aftermath),[citation needed] during season three, the naval services had begun to change their minds, and began to render support to the production team on a script-by-script basis.