At the end of the First World War, two medical officers, childhood friends, work in the same military hospital, where the most seriously wounded arrive from the front every day. Many of them, however, have self-inflicted wounds, they are simulators, who would do anything not to return to combat.
Stefano, from an upper middle-class family, with a father who dreams of a future in politics for him, is obsessed with these self-inflicted wounds and, in addition to being a doctor, is in his own way a cop. Giulio, apparently more understanding and tolerant, is uncomfortable with the sight of blood, is more inclined towards research, and would have liked to become a biologist. Anna, a friend of both of them since university, discounts the fact that she is a woman. In those days, without an influential family behind her, it was difficult to get a medical degree. But she tackles hard, voluntary work at the Red Cross with grit.

Meanwhile, something strange happens among the sick: many mysteriously worsen. Perhaps there is someone deliberately causing complications to their wounds, so that the soldiers are sent home, even crippled, even maimed, as long as they do not return to battle. So there is a saboteur inside the hospital, of whom Anna is the first to suspect.

But on the war front, right towards the end of the conflict, a kind of infection spreads that affects more than enemy weapons. And soon it infects the civilian population as well…