At 19-years-old, Pierre Glendinning Jr. stands to inherit his father's estate. His mother, however, will not allow him to gain control of Saddle Meadows until he is married. She has chosen Lucy Tartan for him, whom Pierre does love and envision a future with. Unfortunately, his happy prospects are complicated when he makes the acquaintance of Isabel Banford, a woman to whom he is profoundly attracted. She claims to be Pierre's half-sister who has been disinherited. Unable to determine the efficacy of her claims, Pierre takes a risk and leaves off his engagement with Lucy to feign an engagement to Isabel in front of his mother. He is immediately disowned.
Pierre travels with Isabel and her friend, Delly, to New York City, abnegating the family estate altogether. In New York, Pierre seeks aid from his close cousin, Glendinning Stanely, but Glen refuses. The three destitutes take up residence in a converted church, where Pierre pursues his writing more seriously. Processing Isabel's story and the potential consequences for his family name if she is correct, Pierre is unable to write the cheery, optimistic stories which publish well. He leans into these darker experiences of his young adulthood, becoming somewhat morbid and self-absorbed.
One day Lucy shows up at their doorstep, hoping to rekindle her relationship with Pierre even without his inheritance. She moves in with the rest of them. As he keeps writing, Pierre has visions of darkness and ancient mythology. He also starts receiving threatening letters from Glenn Stanley, who has now received Pierre's inheritance from Pierre's mother, including Lucy's betrothal, and Lucy's brother. Leaning into the darkness, Pierre becomes consumed by self-loathing and fear for his incestuous love for Isabel and the nasty truth of his father's own arrogance and abandonment of Isabel. He feels betrayed and lashes out at the nearest source -- Glenn Stanley.
Pierre shoots Glen in broad daylight on Broadway and is locked up. Visiting Pierre in jail, Lucy dies of a heart attack when she learns that Isabel and he are siblings. Pierre grabs Isabel's poison vial, downs half of it, and dies. A distraught Isabel finishes the rest.
