A female blackmailer with a disfiguring facial scar meets a plastic surgeon who offers her the possibility of looking like a normal woman.

A US government germ warfare lab has had an accident. The first theory is that one of the germs has been released and killed several scientists. The big fear is that a more virulent strain, named The Satan Bug because all life can be killed off by it should it escape, may have been stolen.

A savings-and-loan bank is robbed; later, a police wiretap identifies meek bank teller Leon Poole as the inside man. In capturing him, detective Sam Wagner accidentally kills Poole's young wife, and at his trial Poole swears vengeance against Wagner. Poole begins his plans to get revenge when he escapes his captors.

A dangerous amnesiac escapes from an asylum, hides in the opera house, and is suspected of getting revenge on those who tried to murder him 13 years ago.

A wealthy playboy gathers a group of bourgeois friends at his isolated beach house for a weekend of relaxation. When bodies start pilling up, they realize they’re trapped with a killer in their midst, sending them in a frenzy to figure out who amongst them is killing the others before they are killed next.