Twelve year old Marcie Horton is not looking forward to spending a lonely and boring summer at her grandparents’ lake cottage. That is until the woods near their home are threatened with development by the wealthy president of the university where her parents teach. Marcie’s attempt to save the forest is aided by her brother, Eric, their elderly neighbor, Al, and a mysterious Indian girl who appears to Marcie in dreams and visions. Their effort is complicated by Marcie’s developing friendship with Kaitlyn Swyndall, the University president’s popular daughter, and the annual sailboat race where Marcie finds herself competing with the wealthy lake property owners against the local residents.
Marcie, Eric and Al try to have the woods protected as a wildlife sanctuary or wetlands and circulate a petition to drum up opposition to the development. When all their efforts fall short of success, their only hope is to have the woods designated as a cultural resource, but no pioneer or Indian site has ever been found around the lake. All the while Marcie is visited by the Indian girl who takes her back to a time when the woods were inhabited by Indians.
Marcie joins a team with Kaitlyn and her brother to compete in the annual sailboat race. As their friendship grows, Marcie is conflicted with her desire to save the woods from development by Kaitlyn’s father and her fascination with their opulent lifestyle. The tension comes to a climax during the sailboat race when Marcie must decide between something she cares deeply about and winning the race. Marcie comes to realize that the kind of person you are is defined not by what you have, but by what you do. She finds that she can accept the Swyndalls for who they are, not for what they have, and most importantly, to accept and love herself.