The film takes place in Sweden around the turn of the twentieth century. Fredrik Egerman is a middle-aged lawyer married to a 19-year-old beauty, Anne. Their two-year marriage is still unconsummated, due to Anne's reluctance. Egerman has a son, Henrik, from his marriage to his late first wife. Henrik is in his early twenties and is studying to be a minister but is currently tormented by his love for his step-mother, who secretly loves him in return. Henrik is distracting himself from his urges by attempting an inconclusive affair with Egerman's lusty young servant, Petra. Between his two marriages, Fredrik had an affair with a prominent stage actress, the beautiful Desiree Armfeldt, but she broke off the relationship. Desiree now has a young son named Fredrik Armfeldt, born shortly after her affair with Fredrik Egerman. (It is implied, but never directly stated, that little Fredrik Armfeldt is the son of Egerman.) Desiree is now having an affair with an army officer, Count Carl-Magnus Malcolm. The Count's wife, Charlotte, is an old friend of Egerman's second wife Anne. Egerman goes to see Desiree one night to pour out his marital troubles to her and ask for her help. He falls into a puddle outside Desiree's house, and Desiree dresses him in the Count's nightshirt. The violently jealous Count shows up and orders Egerman to leave. After Egerman goes, the Count and Desiree argue and subsequently decide to part amicably. When the Count returns home, he tells Charlotte about the encounter and orders her to tell Anne about Egerman's supposed infidelity (though no infidelity actually occurred). When Charlotte visits Anne, she confesses that she loves the Count despite everything, and would do anything to be loved in return. To solve these woes, Desiree has her mother invite all the characters to her country house for
Midsummer Night, the shortest night of the year, a traditional observance in Sweden, when many party-goers stay awake all night until dawn. Desiree and Charlotte become temporary allies. Henrik and Anne, unexpectedly finding themselves alone together in a bedroom, consummate their relationship and elope with the assistance of Petra and her new lover Frid, another servant. Charlotte then joins Egerman in the garden pavilion. Learning his wife is with Egerman, the Count bursts in and challenges Fredrik to a game of
Russian roulette. Egerman loses, but the Count had loaded the revolver with soot so neither party was ever in danger. The Count reunites with his wife, his feelings for her renewed by his jealousy. Desiree comforts Egerman, and he asks her not to leave him. The dilemmas of the four pairs of lovers appear to be happily resolved in the course of a night, said by Frid to have smiled three smiles upon them all. ==Cast==