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.

Twelve-year-old Jack, his sister, and the family's 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.

While at St. John National Park in the Virgin Islands for a seminar on coral reefs, the Landons help a wealthy thirteen-year-old to find his birth mother, who he believes is in danger.