Reported missing, presumed dead, after a UFO incident which has left SID disabled, astronaut Craig Collins turns up alive and well. But as an operation to complete repair work on SID is planned, Colonel Lake and Colonel Grey discover that Collins is not the man he used to be...

While picking up Lt. Lake at the airport, Straker and Lake find that time has been frozen except for them. Sawdust hangs in mid-air, Lt. Ellis is frozen mid-word on a viewscreen, and one man is taunting them, apparently working for the aliens.