The title refers to the hours between 3 and 5 am when, according to Swedish folklore, most people die and most babies are born.

Following a "face-to face" with the camera with Alma, pregnant wife of a painter Johan Borg, the film is mainly a series of flashbacks starting with the couple's arrival on an isolated island. Johan is haunted by images of demons which he draws in his sketchbook. He is tense and sleepless and Alma stays awake with him until dawn, past the hour of the wolf. In the morning Alma meets an old woman who tells her about Johan's diaries which Alma begins to read; we learn from the diaries of Johan's encounters with Baron von Merkens, owner of an estate on the island, and with Johan's former mistress, Veronica Vogler, who disappears as quickly as she materialises Johan is then pursued by a curator, Heerbrand.

A scene with Alma reviewing household accounts is followed by a dinner party sequence at the Baron's estate. Camera shots around the table demonstrate the artificiality of the guests with Alma and Johan ill at ease. Later Lindhorst, an archivist, puts on a puppet performance of a scene from "The Magic Flute" which leads to a discussion about the role of art and the artist. After a walk Johan and Alma are invited by the Baron's wife to view Johan's portrait of Veronica.

On the way home Alma confesses she has read the diaries and is worried for his health. He rejects her and she runs away crying. Later, at home, he tells Alma about his childhood trauma; how he was locked in a dark cupboard. This is followed by a visualised account of Johan fishing from a rock. In a surreal style Johan is attacked by a young boy who he fights off and kills. The boy's head bobs up and down in the water.

Heerbrand comes to call and, inviting them to a party, he leaves a gun. Alma is anxious, Johan urges her to leave. He aims at her and fires. In the next scene Johan returns to the von Merkens where old Mrs. von Merkens directs him to Veronica's room. The Baron tells him of his jealousy, then climbs the wall upside down, like an insect. In a further surreal sequence an old lady pulls off a rubber mask and drops her eyeball into a cocktail, like an olive. Heavily made up, Johan finds Veronica nude on a bier. She appears dead but through his caresses, she comes to life while the grotesque faces of the von Merkens household look on mockingly.

Alma's narrative resumes. Johan fled after he shot her but returned later, writing for hours in his diary. He then packed his belongings and left. Alma has not seen him since. She goes in search of him and encounters the demons that have plagued him. She sees him briefly in the forest being attacked by birds, but the next instant, the place is empty and he has gone.

The film ends with Alma talking to an invisible listener. She questions whether a woman who lives for a long time with a man she loves might not become like him. Or did she lose her husband because she did not love him enough? The monologue ends in mid-sentence.