Berlin Game (Samson)

Berlin Game (Samson) by Deighton, Len. paperback edition. ISBN: 9781402795145.

The opening book in Len Deightons Game, Set, Match series! Brahms Four is the best East German source the British ever had, but now he thinks his cover has been blown--and he desperately wants to come over the Wall and escape from Berlin before hes exposed. There is only one person he still trusts, British agent Bernard Samson of the SIS (Secret Intelligence Service). So Samson, who retired to a desk job five years before, is thrown back into the field. But but before he can even set out on his mission to help Brahms Four, he realizes theres a traitor very close to him. He must find out who it is...and get Brahms to the West before its too late.