When British paratroopers disappear in mid-air during routine jumps, former air force investigator Bob Megan is brought in to solve the mystery.

While making inquiries at a military research laboratory headed by Dr Matthews, he has several encounters with a woman called Lorna who vanishes after each meeting.

Megan learns that all of the missing troopers had received spaceflight training, leading Matthews to theorise that they are being adapted to survive in a non-Earth environment.

The initial idea is promising, 'but it is soon buried under a mountain of sub-plots and unexplained mysterious happenings; and the feeble, talkative script gives the cast little chance to make much impression.

[3] Alan Jones of Radio Times gave the film one star out of five, calling it a "talky, laughably low-budget and hopelessly inept clone of Invasion of the Body Snatchers".