Brewster McCloud lives in the fallout shelter of the Houston Astrodome sports arena, where he spends his days building a winged contraption and doing pull-ups under the guidance of Louise, a mysterious guardian angel. When a serial killer begins running rampant in Houston, ace San Francisco detective, Shaft, is called in to investigate. Brewster develops a relationship with Astrodome tour guide Suzanne, which troubles Louise, who is convinced that any real connection with another human being will ground Brewster and ruin his chances to reach a true bird-like state. As the investigation unfolds it appears that Brewster is not quite so innocent.