A mentally unstable Vietnam War veteran works as a night-time taxi driver in New York City where the perceived decadence and sleaze feed his urge for violent action.

Dr. Bock, the chief of medicine at a Manhattan hospital, is suicidal after the collapse of his personal life. When an intern is found dead in a hospital bed, it appears to Bock to be a case of unforgivable malpractice. Hours later, another doctor, who happens to be responsible for another case of malpractice, is found dead. Despondent, Bock finds himself drawn to Barbara, the daughter of a comatose missionary.