A runaway truck containing the corpse of a slain gang leader rolls into a California nightclub owned by Johnny Cain, a hard bitten former free-lance adventurer. The gang threatens to kill Johnny, unless he solves the murder. The CIA also investigates - because it turns out that the slaying was part of a long-range Communist plan to take over the crime syndicate. Cain's search for clues leads him into a maze of beautiful girls, mysterious Oriental statues and murderous spies.
The Girl Who Knew Too Much is a 1969 neo noir film starring Adam West as Johnny Cain, a nightclub owner and former freelance adventurer who is forced out of retirement when a crime syndicate boss is murdered in his nightclub and investigations lead into unexpected areas. It was the final film of director Francis D. Lyon and United Pictures Corporation.