The story is set in Illyria, fictional central European country, towards the end of World War II. A young man infiltrates into the house of a left-wing politician as his secretary. By order of the Communist party, the young man has to kill the politician, who is suspected of a strategy of compromise with other parties.
| Editing | Gianni Lari | Editor |
| Writing | Elio Petri | Writer |
| Directing | Elio Petri | Director |
| Writing | Jean-Paul Sartre | Theatre Play |
| Production | Nazzareno Marinoni | Producer |
| Camera | Aldo Forni | Director of Photography |
| Sound | Ennio Morricone | Music |
