Set in the year 1917, amidst the backdrop of World War I, the story unfolds in the charming coastal town of Salinas, California. The central characters are Cal "Cain" Trask (James Dean) and Aron "Abel" Trask (Richard Davalos), two young men who are the sons of Adam Trask (Raymond Massey), a modest farmer and chairman of the local draft board. While Aron enjoys his father’s favor, Cal feels overshadowed and resentful, struggling with feelings of neglect.
The Trask family operates a farm in the fertile Salinas Valley. Both brothers were led to believe that their mother passed away, but the film opens with Cal discovering that she is very much alive, managing a successful brothel in Monterey. This revelation shakes Cal and fuels his desire to earn his father’s love.
After experiencing a devastating financial loss due to his father’s failed vegetable venture, Cal ingeniously decides to venture into the bean-growing business, anticipating a significant profit if the U.S. enters the war. In a dramatic turn of events, he seeks financial support from his mother, Kate (Eve) (Jo Van Fleet), who reluctantly lends him $5,000.
As Cal’s business begins to thrive, his relationship with Aron's girlfriend, Abra (Julie Harris), becomes complicated. Abra finds herself drawn to Cal, creating a love triangle that complicates familial bonds. During a surprise birthday celebration for Adam, Cal plans to present his father with the money to help restore the family’s fortunes. However, Adam vehemently rejects the money, viewing it as tainted by the bloodshed of war, which plunges Cal deeper into despair and frustration.
In a fit of rage and jealousy, Cal reveals his brother’s whereabouts to Adam, leading Aron to a fateful decision to enlist in the army, a revelation that leads to a heartbreaking scene where Adam—stricken with grief—suffers a stroke. This pivotal moment throws the family into turmoil, with the townsfolk, including Sheriff Sam "Seth" Barrows (Burl Ives), casting blame on Cal for this tragic turn of events.
Amid the chaos, Cal longs to reconcile with his father, but Adam's condition leaves him unable to communicate. In a poignant moment, Abra encourages Cal to return to his father’s side. As Cal seeks a final connection, Adam's struggle culminates in a moment of clarity where he requests that Cal stay and care for him, hinting at a fragile reconciliation. The film concludes with Cal and Abra by Adam's bedside, suggesting that despite past grievances, healing and understanding may be on the horizon for this fractured family.