Katya, a young librarian, believes in love, but her ideals are crushed by reality. After a string of disappointing affairs, Katya finally finds tenderness and understanding in the arms of her colleague, a journalist called Tanya. But then the First Department interferes: the state security services see this relationship as unacceptable for a Soviet woman.
| Actor | Role |
|---|---|
 Alexey TrifonovChief of the General Department (1952–1960); Head of the Institute (1960–1966) | Chief of the General Department (1952–1960); Head of the Institute (1960–1966) |
 Ekaterina YuspinaLibrarian (1942-1947); Head of the library (1951-1953) | Librarian (1942-1947); Head of the library (1951-1953) |
 Tatiana PolozhyJournalist; Literary editor of Izvestiya Instituta (The Institute News) | Journalist; Literary editor of Izvestiya Instituta (The Institute News) |
| AAlexander EfimovJunior research scientist in the mathematical physics laboratory | Junior research scientist in the mathematical physics laboratory |
 Teodor CurrentzisDau | Dau |
 Radmila ShegolevaNora | Nora |