At the opening we see a bleak shot of Circus Alberti arriving in a small Swedish town. The action takes place at the beginning of the 20th Century. The owner of the circus, Albert Johansson wakes in his cramped wagon, gets out and climbs up next to the coachman Jens. In flashback, Jens tells the story of Frost the Clown and his wife Alma. One summer, seven years earlier, Alma went swimming naked in view of a group of soldiers on artillery practice. On hearing what was happening Frost shed his clown suit and waded into the water to carry his wife out and back to the circus to a background of jeering laughter from the voyeuristic soldiers. The shame of this act impacts on Albert and his mistress Anne. When, smartly dressed, they set out to buy costumes for the circus from the local repertory theatre they face the scorn of the theatre's manager Mr. Sjuberg. Albert then visits his wife and two sons, who run a small store in town, and begs her to take him back. He is rebuffed although she sympathises with his situation. As he leaves he sees Anne coming out of a pawnshop. She visited Frans, an actor in the repertory company, who made love to her in his dressing room and gave her a worthless trinket in return.

Back in the circus wagon, Albert takes his frustration out on Anne but is interrupted by Frost who has a bottle. They get drunk and when Albert takes a gun and threatens to shoot Frost, the clown tells him to shoot Alma's sick bear instead. Albert falls out of the wagon and his mood changed orders the circus tent raised. He and Frost sing a popular song.

The theatre company has been invited to the performance and during her equestrian act, Frans and the rest of the audience, taunt Anne until she falls off her horse. Enraged Albert knocks Frans' hat off with his riding whip and in the fight that ensues Frans kicks sawdust in Albert's eyes leaving him maddened and half blind. Anne intervenes and Albert is carried back to the wagon where he takes his pistol and shoots his own image in the mirror. Then, rushing to the cage where Alma's bear is housed, despite Alma's protests, he kills the poor animal and retreats to the stables to seek solace from the company of the horses. Next day the circus is on the road again by dawn. Albert walks with Frost who tells him of a dream he has had where he shrank to the size of a seed in Alma's womb and then disappeared altogether.

Frost goes into his wagon with Alma, while Albert and Anne walk side by side into the new day.