After an atomic war Phillip Hammer and Marlowe Chandler have spent 15 years on their own in an bunker, stuffed with junk from the 40s and old detective novels. Now, 19 years old, they leave their shelter to find a world full of mutants, freaks and cannibals. They become famous detectives in the struggle for the two keys that could fire the last nuclear weapon.

Warren Stacy, an office equipment repairman, begins murdering women after they reject his advances. To minimize the evidence, Stacy always kills while naked, wearing nothing but gloves, and further evades the law with his strong alibis. Veteran detective Leo Kessler is convinced of Stacy's guilt and begins using questionable methods to catch him.

Michael Long, an undercover police officer, is shot while investigating a case and left for dead by his assailants. He is rescued by Wilton Knight, a wealthy, dying millionaire and inventor who arranges life-saving surgery, including a new face and a new identity--that of Michael Knight. Michael is then given a special computerized and indestructible car called the Knight Industries Two Thousand (nicknamed KITT), and a mission: apprehend criminals who are beyond the reach of the law. The series depicts Michael's exploits as he and KITT battle the forces of evil on behalf of the Foundation for Law and Government.