Soldier Smelkov is tasked with running into the city at night for vodka. Instead of money, he was given several ordinary-looking pills, which he had to exchange for a bottle. The task was successfully completed, but the sergeant who sent Smelkov to the city soon died from poisoning. Smelkov talks about the night’s adventure to his friend, captain of the medical service Goryashchev. Goryashchev promises Smelkov to sort it out, but a few days later the captain’s corpse is found with a bullet through his head. The official conclusion is suicide. And the reason seems to be compelling: unrequited love for a nurse named Lucia, who works in a military hospital. But Smelkov is not satisfied with this version. He feigns illness and ends up in the same hospital. There he discovers the secret sides of the crime into which he unwittingly found himself drawn...