A biographical story about significant Czech dramatist, writer and actor Josef Kajetán Tyl.

An unknown gang has again broken into a van containing money from the European bank. Banker Sam Hamilton decides to use an armoured car for the next money transport. He hires racing driver Charly Allan as the driver. Allan is invited to Hamilton's house for a party. During a dance with the banker's daughter Bessy he is attacked by bandits, pushed to the ground and Bessy is kidnapped.

Professor Grant signs a contract with Dr. Selin for the sale of his invention of cold light with the plans for his invention being kept in Grant's apartment. The negotiations are secretly heard by the illusionist Durk, who wants to seize the invention. A few days later Selín is found dead, killed by a light bulb filled with poisonous gas. Durk performs at the birthday party of Grant's daughter Anna and seizes the plans for the invention.

The problem of companionship marriages , i.e. marriages determined by purely practical rather than emotional motives, is addressed with all its pros and cons using two relationships . The four protagonists are the student Erich Helmholz and his wife Elli, a seamstress, both a happily married but not in love couple, and the consultant's daughter Maria, who comes from the best "stable" and who, in her ignorance, first allows herself to be impregnated by any man (without really understanding how this could have happened) and then, under pressure from her horrified parents, enters into a companionship marriage with another man who has brilliant career prospects.