The fourth and final season of Knight Rider, an American television series that ran from Sept 26, 1982 to Apr 4, 1986, began September 20, 1985, and ended on April 4, 1986.

Hasselhoff, knowing that the show was coming to an end, attempted to make a "series finale" and helped conceive the story "The Scent of Roses" with his wife at the time, Catherine Hickland, who played Michael's love interest Stephanie Mason in past episodes.

Seeing as KITT was nearly destroyed in the armored car attack, Bonnie cannot repair him without Devon Miles' assistance or FLAG's facilities.

A plane that Bonnie is traveling on is hijacked by a group of men led by an ex-intelligence agent (Ron O'Neal) who demands money and the release of "political" prisoners.

Michael and KITT manage to track them to a military bunker that was designed to keep high-ranking officials safe in the event of terror attacks, and is surrounded by mines and other automated security systems and assumed to be impossible to break into.

Michael and KITT investigate the grounds of a movie studio where unexplained accidents on the sets are thought to be the work of a legendary stage phantom.