A sealed American military train leaves Berlin nightly for West Germany with every passenger accounted for, thus is not subjected to Russian inspection en route. On this particular night the routine is broken; while the train is held up by a signal, unknown to the Americans an East German refugee clambers aboard. The Russians become sus­picious and the train is held up at Marienborn; a tense situation develops, with both sides anxious not to provoke an incident.

The attitudes of both the Americans and Russians are presented fairly and sympathetically, while the tension and claustrophobia of the train setting is well sustained by the director to produce a con­vincing film.