A grumpy ghost named Scratch is eternally cursed to be in the presence of polar opposite Molly McGee, a cheerful tween.

Tween optimist Molly McGee lives to make the world a better place, fix what has gone wrong, and spread joy. Meanwhile, cantankerous ghost Scratch lives to make the world a worse place, break what has gone right, and spread misery. When a curse from Scratch backfires, he finds himself forever bound to Molly. Despite that, Scratch and Molly form an unlikely friendship that guides each of them through the ups and downs of their respective worlds.

In the human world, 13-year-old optimist Molly McGee arrives in her new hometown of Brighton, only to discover that her new house is already occupied by a grumpy ghost named Scratch. Scratch curses Molly in an attempt to get rid of her. However, the curse backfires on Scratch, who now finds himself forever tied to Molly. After a rocky introduction between Scratch and Molly's family, Scratch and Molly form a tentative friendship. Meanwhile, in the Ghost Realm, the level of misery in Brighton decreases slightly; the Ghost Council's Chairman notices this. While initially antagonistic toward her, Scratch opens up to Molly over-time, and their friendship strengthens.