Dr. Arthur Calgary visits the Argyle family to return an address book lost some time ago by Jack Argyle, only to find out that Jack has been executed for the murder of his mother. Calgary can prove that Jack was innocent. In spite of opposition from a hostile family, he is determined to solve the crime.
A space shuttle mission investigating Halley's Comet brings back a malevolent race of space vampires who transform most of London's population into zombies. The only survivor of the expedition and British authorities attempt to capture a mysterious but beautiful alien woman who appears responsible.