David James Elliott stars as Lieutenant Commander "Harm" Rabb, Jr., a brave, outstanding Navy Lawyer and officer in the Judge Advocate General (J.A.G.) Corps. His missions are to investigate and prosecute all crimes, accidents, acts of terrorism and espionage related to the Navy and Marine Corps. Playing the diverse roles of investigator, prosecutor and defense attorney, Harm and his partner Major Sarah "Mac" MacKenzie (Catherine Bell), use their intelligence and determination to uncover the mysteries behind cases involving murder, treason, espionage and other high crimes to bring world-class criminals to justice.