I

Glienicke Bridge—also called the Bridge of Spies—lay on the western edge of the city of Berlin. Before the wall, it provided Berliners and Potsdamers alike a passage across the Havel River that flows from the Mecklenburg Lake District in northern Germany through Berlin to Havelberg in western East Germany, where it connects with the River Elbe. After the wall was erected, it cut off Potsdam from West Berlin and the bridge became obsolete. Well, almost obsolete as it was still used to exchange spies between the United States and the Soviet Union. But commoners from Potsdam and Berlin, who were used to crossing the bridge to either go to work or visit friends and relatives, could no longer pass.

The Soviet occupation powers closed the bridge, built in 1907, to West Berliners in May 1952. Interestingly, the citizens of East Germany were still allowed to use it, but that didn’t last long. When the construction of the Berlin Wall started on August 13, 1961, they were no longer welcome at the bridge, either.

When James Hart quietly climbed down the riverbank at that moonlit night, he stopped for a second to admire the beautiful architecture of the bridge. He remembered how his dad had taken him to the bridge in the fall of 1945, a few months after the war had ended in Europe, and how they were turned back because the bridge was badly damaged and no one was allowed to use it. In the coming months and years, however, the bridge was rebuilt—although not even God in heaven would know what for, if just less than a decade later it was to be closed again. And now, James Hart, a major of the United States Army, Berlin Brigade Intelligence Division, was getting ready for a dangerous mission under the green, fully functional, but nevertheless a useless bridge, held in the iron fist of the Soviet military.

The time on his wristwatch showed oh-four thirty-four, or four thirty-four in the morning. There’s plenty of time, he thought, when he slowly, without making a sound, slid himself from the soft, grassy riverbank under the bridge. He jumped up to get a hold of the bridge, and pulled himself to the lower bearing of the construction on the southern side of the bridge. He was wearing his camouflage uniform and had taken off all markings of his rank, battalion and country, thus hoping that the green clothing would smoothly merge with the green of the bridge and make him almost invisible. He checked his sidearm, took the safety off, and waited.

He was about to do what the U.S. Army hadn’t tried before. At exactly oh-five hundred hours that morning, a prisoner exchange was to take place on the Bridge of Spies, a top secret one at that—nobody but a few select officers in the Intelligence Division and the C.I.A. knew about it.

A week earlier, the East German secret police—the Stasi—had captured a C.I.A. operative in East Berlin. Two months before, a deserter from the Soviet Army—and to make things even worse, a conscript—had shot and killed a high-ranking Soviet officer. And not only was the officer a decorated World War II veteran, he was, unfortunately for the Soviets, the deputy director of the K.G.B.—the Soviet internal intelligence agency—in Berlin.

The Americans wanted their agent back, and the Soviets were eager to hang the killer of their intelligence chief.