 CIA-agent Jack Grant is looking forward to a well-earned holiday with his family. But it doesn t come to that. The CIA s contact within the most important informant ring in East Berlin has not been heard from for a while. The specialist Grant is asked to search behind the Iron Curtain for five American agents who have disappeared without trace. Grant secretly travels to East Berlin. According to plan, he swaps identities with an East German citizen and takes over his passport, car and flat. He is entirely dependent on himself. As long as the weak point in the informant network is not found, he must not trust anybody. After only a few hours there an unforeseen event takes place. The neighbour of the man whose identity Grant has taken has discovered the switch. In order not to endanger his mission Grant has no other choice: he must kill the man. Grant is now in danger of being sought for murder. He cannot use the flat as a refuge any longer. He tries to find a former CIA contact who is a waiter in a café. The man, obviously scared, declines to help Grant. The waiter s colleague, Anneliese, hears about Grant s flat problem. The young, good-looking woman who doesn t know Grant works for the American secret service, suggests that he live with her. Grant accepts the offer. Grant s only clue points to an employee of East German State Security, a man named Oberg. Grant has evidence that Oberg is a homosexual and he can therefore put considerable pressure on the civil servant. Grant persuades Oberg to get him information about the vanished agents. In return, he offers to arrange Oberg s escape to America. But although the State Security official goes to considerable trouble, he cannot find out anything about the whereabouts of the American agents. The only thing he is able to report is the forthcoming secret visit of Soviet leader Mikhail Gorbachev to the GDR. This information leads Grant onto a new trail: There must be a connection between Gorbachev s planned visit and the mysterious disappearance of the American agents. Grant suspects that certain powers within the Russian and East German secret ser-vices are planning an attack on Gorbachev and the blame for it will be planted on the American agents. A relapse into the Cold War is looming up. Grant visits the British Embassy to try and find support. But their agreement only comes reluctantly. They identify Anneliese, the waitress in the café, as their contact. Anneliese, who is now much more than a mere flat-mate to Jack Grant, works for British Intelligence. She is at the centre of the most important British informant ring in East Germany. To his great surprise, Anneliese reveals to him that the head of State Security himself, General Vogel, is a British agent and head of the spy ring. Grant is suddenly arrested. In his quiet cell it becomes clear to him that Anneliese and Vogel are double-crossing him. Vogel is not only a double agent - together with a Russian general he is the real organizer of the plot against Gorbachev. At night the door to Grant s cell is opened. To his absolute amazement Schnabel, the director of East German State Security, second only to General Vogel, helps him escape. The seriousness of the situation requires special care. Schnabel knows that Grant is the only person who can help him prevent the attempt on Gorbachev s life. He refers Grant to two officials whom he regards as trustworthy, and who will support Grant. There is no time to be lost. The Soviet leader s arrival is almost due. A quarter of an hour before Gorbachev is expected, Grant and his companions drive along the intended route in a black limousine of the type that will be used for the state visit. One of Grant s escorts sits in the back of the car dressed up to look like Gorbachev. Along an unfrequented part of the route they are promptly attacked by masked soldiers. There is a vicious struggle from which Grant emerges victorious. As Grant had expected, he finds the five missing US agents in the attacker s car: tied up and doped with drugs. The conspirators from East Germany and the Soviet Union had planned to leave them at the scene of the attack so that all the evidence would point to them. Meanwhile, the limousine with the real Gorbachev drives past safely and peacefully and arrives on time for the important talks. As Schnabel, the head of East German Security, tells him, Grant can be sure of Gorbachev s appreciation.