A boy befriends a girl living with her guardian and discovers that she is a vampire; after an experimental germ weapon is accidentally released in a small Iowa town, both citizens and soliders try to contain the virus which makes its carriers homicidal; in a final secret mission to the moon, U.S. astronauts discover a crashed Soviet spacecraft and the body of a cosmonaut killed by unknown causes; after two men wake up on a spaceship with no memory of how they got there, they discover other humans on board as well as mysterious monsters intent on destroying them.