Professor Turwid is conducting research on a vaccine to combat encephalitis. The medical community is skeptical about this. Suspecting his wife of having an affair with a younger colleague, Count Łański, he fakes his own death. The only person who knows his secret is his servant Feliks. Over the next few years, he passes on information about the situation of his wife and daughter. The professor knows that his suspicions were completely unfounded and that his wife devoted herself entirely to raising their child. After many years, he returns to Warsaw, where he starts working at a clinic and, together with Jerzy, his daughter's future fiancé, completes work on the serum. There is a chance to return to his family, but it may already be too late.