Montgomery Clift, Hardy Krüger, Macha Méril, David Opatoshu, Christine Delaroche, Hannes Messemer, Karl Lieffen, Uta Levka, Roddy McDowall, Johannes Buzalski, Eckart Dux, Jean-Luc Godard, Eduard Linkers, Franz Rudnick, Rolf Zacher
An American scientist is sent by the CIA to East Germany to retrieve a secret microfilm from a Soviet scientist interested in defecting to the West but the Stasi secret police's surveillance complicates matters.