Jack, Ashley, and their parents visit Hawaii where they meet a Vietnamese boy who is going to live with his American grandfather whom he has never met, and are pursued by the Goddess Pele.

The Landons are in the Caribbean, in Virgin Islands National Park, to figure out what is destroying the coral reefs and causing the hawksbill sea turtle to disappear. Jack and Ashley find themselves hopelessly entangled in the mysterious life of Forrest Winthrop IV, the adopted son of a U.S. diplomat. Why is he so anxious to save an island woman named Cimmaron? What secret do they share? Follow the action to Jumbie Bay and see what the full moon reveals.

The Landon family travels to Glacier National Park to investigate why grizzly bear cubs are disappearing and become involved with a ten-year-old Mexican runaway boy.

Twelve-year-old Jack, his younger sister, and the family's teenage foster child Troy go to Yellowstone National Park, where Jack's mother, a wildlife veterinarian, is investigating the report that wolves reintroduced to the park have killed a dog there.

Originally published: Washington, D.C.: National Geographic, 2002.

For use in schools and libraries only. The Landon family makes a trip to Death Valley National Park, accompanied by a mysterious new foster child, 14 year-old Leesa Sherman.

While visiting the Everglades National Park with their parents, the Landon children uncover the mystery of dying manatees and learn important lessons about the natural environment.