Summer vacation in their small Maine town does not look too promising until twelve-year-old Gina and four of her friends make a pact to become millionaires before school starts in September.
Twelve-year-old Greg, who has always been good at moneymaking projects, is surprised to find himself teaming up with his lifelong rival, Maura, to create a series of comic books to sell at school.
At the same time that the Alden children's efforts to raise money for a new hospital wing are being sabotaged by nasty tricks, they find their attempts to befriend the new girl, Beth, frustrated by her strange behavior.
Calvin tries to earn money to buy Stella, the babysitter, a present for her sixteenth birthday because he feels guilty for taking advantage of her allergy to cats.