Sisters Stacy and Gina Cavallaro have a tempestuous relationship both on the baseball field (playing for opposing Little League teams) and at home with their grandmother, who happens to be a kindly witch. Stacy’s team, the Rooks, is an utterly hopeless laughingstock, perpetually coming in last. After a squabble with her sister, Gina purloins a bit of her grandmother’s magic and casts a spell on Stacy’s glove. Although she’s not entirely sure of the results, Gina’s spell unexpectedly works, and soon the Rooks have a new member among their ranks: a lumbering zombie with a penchant for chewing baseballs over brains. Furious, Stacy conjures her own retaliatory spell, leaving Gina plagued by a pernicious poltergeist. Whether the sisters like it or not, they soon find they must work together to save the league, their friends, and each other.
