Meet the Melendys! The four Melendy children live with their father and Cuffy, their beloved housekeeper, in a worn but comfortable brownstone in New York City.

A summer that promises to be eventful turns into something extra special when the four Melendy children become friends with the orphaned Mark Heron.

Into the Four-Story Mistake, an odd-looking house with a confused architectural history, move the Melendy family -- Mona, Rush, Randy, Oliver, Father, and Cuffy

The fourth and final book in Elizabeth Enright's Melendy Quartet, in which the two youngest Melendys experience a year-long treasure hunt adventure.

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