Norden, a pharmacist's mate in the Navy during World War II, is on the night watch at a naval prison hospital. Including the new prisoner they got just that night, there are twelve people for him to watch. Having failed to get any sleep during the day, Norden struggles to stay awake as he watches the prisoners and tends to their medical needs. The guard had to wake him up when he delivered the new prisoner, interrupting Norden's dream about a court martial. His mind gets foggy, making him forgetful and suspicious of the new prisoner. Norden hopes that the doctor will arrive soon to do his rounds. One of the prisoners, Garnes, has been there the longest. He had been shot while trying to escape, and the pain from his wound made it difficult to sleep. He has become friendly with Norden, and thanks the medical officer when he opens up the drainage tube from Garnes's wound. Garnes tries to go back to sleep, but he ends up watching Norden and the other prisoners. When a plane lands nearby, another of the prisoners, Morrisson, lets out a cry. He panics and scratches himself, believing that he is still on a beach under enemy fire. Norden calms him down and then goes back to his desk. Shortly after this, a nearby prisoner named Rosbrough, gets out of bed and hides in the latrine because he suffers from paranoia. Norden goes and talks him back to bed. A little while later, Rosbrough gets out of bed again. This time Norden fails to calm him down, and Rosbrough tries to strangle Morrisson. Norden struggles to get Rosbrough off of Morrisson, but he is aided by Kummer, the new prisoner. Together they get control of Rosbrough and pin him on the floor. Norden tells Kummer to fetch the guard, but at that moment the door opens and a guard and the doctor enter. The doctor tells Rosbrough to get up and stop pretending to be unwell. After arguing for a minute, the doctor decides to go get a straitjacket to restrain Rosbrough. As he does so, however, Garnes lets out a cry from his bed, pointing towards the latrines where he saw Kummer go during the commotion, taking the belt from a bathrobe with him. The doctor pulls back a shower curtain to find Kummer, who had just stepped off of a chair, attempting to hang himself. The doctor cuts him down and sees that Kummer's neck was not broken. He sends the guard for equipment and more medical personnel. As Norden sees the prison hospital fill up, he realizes that there is little he can do and that his night watch is practically over, so he goes to sit back down at his desk. As he does so, he falls asleep, dreaming that he is being tried at a court martial and has been pronounced guilty.