The discovery of a lottery win triggers a catastrophic collapse of morality and sanity for a San Francisco dentist and his wife. McTeague, a man of limited intellect and brute strength, operates an unlicensed dental practice until his marriage to Trina Sieppe introduces a sudden, life-altering fortune. As the couple navigates the pressures of urban poverty and the psychological weight of their newfound wealth, their relationship devolves into mutual suspicion and avarice. The narrative employs a third-person omniscient perspective to observe the characters' descent, emphasizing the deterministic influence of heredity and environment on their tragic trajectory.

Readers and critics frequently identify this work as a foundational example of American naturalism, noting its unflinching look at human degradation. Discussion often centers on the author's clinical, almost detached observation of the characters' moral decay as they succumb to their baser instincts. Many highlight the effectiveness of the San Francisco setting, which functions as a catalyst for the characters' isolation and eventual ruin. The narrative is often praised for its refusal to offer moral redemption, maintaining a consistent tone of grim inevitability throughout the text.