Eleven-year-old Portia and her family return with cousin Julian to the site they visited the previous summer, this time to take possession of a large Victorian house, unoccupied for fifty years and full of treasures and secrets.

Portia and her cousin Julian discover adventure in a hidden colony of forgotten summer houses on the shores of a swampy lake.

At first Henry's very neat cousin doesn't like the cookies from under his bed or Mudge's slobbery kisses, but when they all play frisbee, she begins to enjoy her visit.

When Henry's cousin Annie prepares to move in next door, he and Mudge help calm her fears.

Cammy's only trouble in life is a cousin named Patty Ann who overshadows her in every way - until suddenly, Patty Ann is no longer around. Cammy has a happy life and a great family, except for one little problem: a cousin who thinks she's better than everyone else. It's true that Patty Ann is beautiful, talented, and bright, but to Cammy she's also vain, conceited, and mean-spirited. Sometimes Cammy wishes that Patty Ann would disappear, just vanish...