While at the fair, a young maid, Julie, falls head over heels for the smooth-talking fairground worker Liliom. They move in together but Liliom, now out of work, becomes increasingly violent towards her. When Julie falls pregnant, he begins to think of the life he could give the child if he had more money. Things spiral out of control: Liliom attempts a hold-up that goes wrong and commits suicide before he can be arrested. Two of 'God's detectives' take him to trial in heaven, where he is sentenced for his violent behaviour towards Julie. Sixteen years later, Liliom leaves purgatory having expiated his sins. He is allowed to return to earth for a single day to meet his daughter and leave her a gift. However, the girl takes him for a vagrant and refuses what he has to offer. Beside himself, he strikes her.

Molnar's play achieves catharsis in the simplest manner. The author's goal is to make the audience feel genuine compassion towards Liliom. The latter's heart is hidden behind ugly words, misplaced pride and misdirected, loutish rebellion.
Molnar portrays the harrowing tale of a love smothered by unspoken feelings: it is this emotion and frustration at being unable to communicate that cause his downfall. The events unfold on the eve of the twentieth century in the working-class district of Budapest, where policemen, smooth-talkers, maids and soldiers all rub shoulders on an everyday basis.
The play's characters are drawn from a highly underprivileged background and have trouble expressing themselves. None can find the right words and are forced to communicate in weak, empty language. The author succeeds in illustrating the triviality and brutality of this language without losing the fragile modesty of the play. While unable to convey their emotions to one another, Julie and Liliom make us acutely aware of their helplessness and distress.
Today's cities all have their own Lilioms, whether the big wheel turns in Berlin, Saint-Ouen, Vienna or Coney Island.