In a post-apocalyptic world, a young woman named Ann believes she is the last survivor until she encounters two strangers, John and Caleb. As they form an uneasy bond, tensions rise, and a complex love triangle emerges in the secluded valley they now call home. The trio must navigate their emotions and conflicting desires as they strive for companionship, survival, and hope in a world where trust is a rare commodity. "Z for Zachariah" is a gripping tale of human connection, resilience, and the fragile balance between love and betrayal in the face of a shattered society.