A biographical film about a Czech doctor, Dr. Jánský. The athletically inclined medic Jánský successfully completes his studies. He wants to become a surgeon, but finds himself in Professor Kuffner's psychiatric clinic, where, together with his colleague Kozdera, he tries to uncover the connection between blood clotting and mental illness. They make the surprising discovery that human blood can be divided into four groups and thus prevent it from clotting during transfusions. However, Jánský's discovery is met with misunderstanding by the Czech medical community...
Is The Secret of Blood on Netflix? Unfortunately the movie The Secret of Blood is not yet available on Netflix.
| Art | Bohuslav Kulič | Production Design |
| Directing | Marie Moravcová | Assistant Director |
| Writing | Jan Werich | Screenstory |
| Sound | Otakar Pařík | Conductor |
| Costume & Make-Up | Aša Teršová | Costumer |
| Writing | Otakar Kirchner | Screenstory |
| Costume & Make-Up | Gustav Hrdlička | Makeup & Hair |
| Sound | Josef Zora | Sound |
| Directing | Rudolf Jaroš | Assistant Director |
| Production | Ladislav Terš | Production Manager |
| Production | Jaroslav Vlk | Unit Production Manager |
| Writing | Vladimír Neff | Story |
| Writing | Martin Frič | Screenstory |
| Camera | Bohumil Hába | Assistant Camera |
| Directing | Martin Frič | Director |
| Camera | Jan Stallich | Director of Photography |
| Art | Josef Pavlík | Set Decoration |
| Costume & Make-Up | J. M. Gottlieb | Costume Design |
| Writing | Vladimír Neff | Screenplay |
| Editing | Jan Kohout | Editor |
| Sound | Dalibor C. Vačkář | Original Music Composer |