Country Dr. Robert Koch is desperate: a tuberculosis epidemic is decimating the children in his district and no one is able to do anything about it. Every fourth child is already sick and the parents must helplessly watch as their young ones die. Now Koch is undertaking to find the cause of the tuberculosis --- something he has already been working on for years --- which has been causing this plague of illness. His work is made more difficult by envy; for example, that of his teacher, who was wounded defending his honor. But his greatest obstacle is the famous Berliner scientist and Reichstag deputy, Privy Councilor Rudolf Virchow: He is extraordinarily skeptical of Koch's theory, that the cause for tuberculosis is a bacteria.

At a ball at the Metropol, the married Margit gives a harmless kiss to a one-time friend from her childhood and cousin, Eberhard. The two notice, however, that Margit's ill and jealous husband observed them from a distance, because he recognized the coat she recently purchased. Quickly, Margit asks the salesgirl Trude to put on her coat and meet Eberhard in the lobby. Things take a decidedly different turn, however, when Trude and Eberhard fall madly in love with each other.

Lisa's marriage is all in all quite happy; unfortunately, her husband never listens to her when it comes to buying new things. To change this situation, she fakes a loss of memory and pretends not to know who her husband is. When he calls the young psychiatrist Dr. Spinelski for help, Lisa acts, as if she believes he is her husband; and as part of the therapy, Spinelski makes sure that Lisa gets everything she wants. Finally, Lisa comes to the conclusion that she'd rather have her real husband and so pretends to fall for him, whereupon they start a new life together. I'll remember to try that the next time I'm not allowed to buy some beer.

Sabine Heitmann, the young boss for the shipping company Heitmann, has become friends with Michael, the First Officer and Helmsman of the ship, the "Sabine Heitmann". He only knows Sabine by her first name and doesn't know that she's the boss. When he discovers the fact, however, he gets pissed and refuses to accept his promotion to Captain. Then the shipping company gets a lucrative offer: In a competition with another shipping company, they need to reach Baltimore in 18 days and pick up some freight. Whoever can move their rear ends faster, gets the very profitable contract from an American firm (correct me if I'm wrong, but didn't this sort of thing sink the Titanic?). Together with Michael, Sabine comes up with a plan, which should have them win the contest. The upshot? She wins back his heart and he becomes Captain.

1900: Much to the chagrin of Baron Uhlendorff in Schoneberg, the city of Berlin is expanding. But what is much worse is that his son George is in love with Traute, the daughter of the master carpenter Schradecke. So the son must leave for South America as a diplomat and Father Schradecke has to intercept his letters to his daughter. Traute is inconsolable; 1913: The early days of the small artisans have now given way to them becoming big businessmen. Traute continues to wait for George in spite of the stubborn proposing by the carpenter Paul Buttner.

Teresa is a young, always cheerful woman, who has a harmonious marriage with the writer Peter Duhren. Unfortunately, it’s so harmonious, that he’s uncapable of writing a novel. So he decides instead to write a book about his own marriage. Teresa is so horrified about this indiscretion, that she asks for a divorce. Peter is prepared to withdraw the book from circulation to save his marriage, but when he finally is about to do so, it becomes a bestseller. Despite attempts at reconciliation, Teresa leaves his. So much for the alleged ‘harmonious’ marriage.