Mathieu Delarue, a philosophy professor in pre-war Paris, struggles to reconcile his desire for absolute personal freedom with the impending moral and political responsibilities of a world on the brink of conflict. Mathieu seeks to maintain his autonomy by avoiding permanent commitments, yet he finds himself entangled in a series of crises involving his pregnant mistress, his brother, and his own financial instability. The narrative follows his attempts to secure an abortion for his lover, Marcelle, while he grapples with the realization that his inaction is itself a choice. Set against the backdrop of a tense, pre-war France, the story utilizes a third-person limited perspective to examine the internal contradictions of existentialist thought. The world is defined by the looming threat of war and the claustrophobic social expectations of the Parisian intellectual class.

Readers and critics frequently analyze the work as a foundational exploration of existentialist philosophy within a narrative framework. Discussion often centers on Mathieu's perceived paralysis and whether his pursuit of freedom constitutes true liberation or merely a form of evasion. Many highlight the effectiveness of the setting, noting how the impending war serves as a catalyst for the characters' moral dilemmas. The prose is often described as dense and intellectually rigorous, requiring patience from the reader to fully grasp the philosophical underpinnings of the protagonist's choices.