The "Concordia" trading company in Würzburg is a secret headquarters of the MID, a secret service agency of the US Army. For years, espionage, sabotage, and diversion operations originated from here in order to undermine the Socialist Republic of Germany. A favorable moment for a military attack approaches and plans are developed. These plans are placed in the hands of Major Collins, who keeps them in a safe. Hansen has worked for him for many years, but also for the Stasi as a double agent. Security Chief Colonel Rock knows there is a leak, but Hansen has passed every test thrown at him. He is trying to deal with his current assignment: acquiring the plans so they can be made public. His mission is to get them out of the safe and into the GDR without getting caught.

In a casino in a We'5t German health resort, one often sees Sybille - an attractive young student actress. With her winnings from the roulette table, she attempts to finance her studies. Despite a rather lucky streak, her winnings are a little on the lean side. She doesn't, however, gamble with her own money but with that of Dr. Busch, a lawyer, who likes to stay in the background with the argument that gambling houses are not the proper turf for a serious lawyer. From him, Sybille receives only a small share of her winnings later, and only through the intervention of Gerhard Fischer, a journalist, does Sybille come to realize her role in Dr. Busch's fraudulent scheme.

A film about the historical uprising of the seamen in Kiel: During the Russian October Revolution of 1917, German and Russian soldiers start to solidarize with each other. By disarming the officers, machinist Henne Lonke and stoker Jens Kasten prevent the attack on a Russian freighter. When German admiralty gives out orders for operation "Nibelungen", which would lead the German fleet into a suicidal attack against England and quell the revolutionary spirit, seamen and soldiers from different political backgrounds unite in protest.

Former East German engineer Erich Becker had been lured to West Germany by promises of a high reward. Now residing in Stockholm, he is recalled to serve as a spy in the East. He is to convince Dr. Jadenburg to flee from the GDR with the help of his daughter Hanna, who works for the West. While travelling on the train with Hanna, he is told that he is also to murder another agent who betrayed and now works for the Stasi. The traitor is revealed to be a former friend of Becker, Harry Korb.