When a UFO attacks a plane, the body of an alien is found. Is this part of an alien plan to take over the world? Supreme Headquarters Alien Defence Organization will find out.

Colonel Foster is a test pilot whose aircraft is caught up in a battle between a UFO and a SHADO rocket. When he wakes up in hospital nobody will believe his story of what he saw.

Straker must choose between risking everyone's life to save his young son, or stopping a downed alien spacecraft.

Aliens plan to infiltrate SHADO headquarters from a base under the ocean.

SHADO blames a private business firm's geological scanner for the disruption of visual and audio transmissions from the moon.

Foster risks his life and reputation to prove the abundant debris orbiting Earth creates potentially deadly threats to friendly vessels.