It's been eighty-six years since the Red Sox won a World Series. Eighty-six years cursed.
Twelve-year-old Oscar Egg believes he is cursed, just like the Red Sox. His real parents didn't want him, and now his adopted mom has dumped him off to live with his strange, sickly dad.
But there's something Oscar doesn't know. The Boston Red Sox really are cursed, and not just because they sold Babe Ruth in 1919. Someone deliberately jinxed the team, and the secret to breaking the Curse lies deep below Fenway Park, with Oscar's dad and the Cursed Creatures, a group that has been doomed to live out their miserable lives below Fenway until the Curse is broken.
Oscar knows he can be the one to break the Curse, allowing the Red Sox to finally win the World Series and setting the Cursed Creatures free. But some of the creatures are angry. Some don't want the Curse broken. Some want Oscar, and the Red Sox, to fail and remain cursed forever.