An undercover mission beyond the Iron Curtain to recover a defected scientist goes disastrously wrong - a classic early Cold War thriller from the acclaimed master of action and suspense.

Doctor Jennings, a noted scientist in possession of a precious secret, has gone over to the Soviet Union. It is Michael Reynolds' mission to get him back.

To penetrate behind the Iron Curtain and reach his quarry will be difficult enough, especially with the fearsome Hungarian Secret Police watching his every move.

Then, from inside that terrifying organisation, comes the offer of help - the question is: can it be trusted?