A relentless psychological horror novel by Stephen King. Set in the rural town of Castle Rock, Maine, the story follows Donna Trenton and her young son Tad, who become trapped inside their broken-down car on a sweltering summer day.

Their only obstacle to escape is Cujo, a once-friendly 200-pound Saint Bernard who has been bitten by a rabid bat. As the disease takes hold, the gentle family pet transforms into a relentless, unpredictable killer. With temperatures rising, food and water running out, and help nowhere in sight, Donna must summon extraordinary courage to protect her son and survive.

Unlike many of King's novels, Cujo contains no supernatural villain. The terror comes from realistic circumstances, human mistakes, and the devastating effects of rabies. Alongside the survival story, King explores themes of family, guilt, fate, fear, and the ordinary tragedies that can spiral into unimaginable horror.

Tense, emotionally charged, and deeply human, Cujo is widely regarded as one of King's most suspenseful and psychologically intense novels.