Desc: Stellenweise Glatteis: Directed by Wolfgang Petersen. With Günter Lamprecht, Dorothea Moritz, Léonie Thelen, Karl-Heinz von Hassel. One day locksmith Karl Maiwald accidentally discovers a special secret of the intercom on the desk of the chief secretary, which was installed in many rooms of the factory. With the help of a technical trick it's become a listening device.