The arrival of a mysterious and charismatic student at a provincial school triggers a lifelong obsession with a fleeting, dreamlike encounter. The protagonist, Augustin Meaulnes, disrupts the quiet life of his friend François Seurel when he wanders away and discovers a secluded estate filled with strange festivities. Driven by the memory of a girl he met during this brief interlude, Meaulnes spends his subsequent years attempting to relocate the lost domain. The narrative is presented through the perspective of Seurel, who observes his friend's internal conflict as he navigates the tension between his romantic fixation and the demands of reality and friendship.

Readers and critics frequently discuss the novel's unique ability to evoke the specific, melancholic atmosphere of late adolescence. Discussion often centers on the balance between the realistic depiction of French provincial school life and the surreal, almost mythical quality of the lost domain. Many highlight the effectiveness of the narrator's voice in grounding the more fantastical elements of Meaulnes's quest. The work is widely recognized for its refusal to provide easy resolutions, focusing instead on the enduring nature of youthful longing. Scholars often point to the text as a foundational example of early twentieth-century French fiction that captures the fragility of memory.