John Stack awakes to find himself in a hotel bedroom in Spain, with a partial loss of memory. He knows that he is working for British Intelligence, and that Berak is dead and Gunter has taken over. He has to get to Berlin as quickly as possible and fill the missing gaps in his memory. But the opposition is still looking for him. He goes to the Doctor who offers him help if he will negotiate the escape of an East German across the Wall. Stack agrees, and returns to Berlin with the girl, to find that his two missions are closely linked together.