Gloria Skurzynski

An adventurous rescue set in the time of medieval knights, castles, bandits, and music.
 
Before their father returns to France from the Crusades, daring Alice and musical Roger set off on their own journey: to find their long-lost uncle. But on the way, the siblings are kidnapped and locked in an ancient hidden tower. To finish their quest, they need to escape—and fast! Can Alice use her courage to slip away and find help?

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Tired and disillusioned, Corgan tries living a more peaceful life on Nuku Hiva, but soon must confront his nemesis, Brigand, for the last time

While lost in a tunnel at Carlsbad Cavern, thirteen-year-old Jack, eleven-year-old Ashley, and their eight-year-old foster brother, Sam, think bats and darkness are their worst problems, until they stumble across thieves

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

Jack, Ashley, and their unreliable new foster sister set out to solve the mystery of why whales are beaching themselves at Acadia National Park

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

Visiting Zion National Park with his family, twelve-year-old Jack encounters two mysteries, the strange behavior of a band of wild mustangs and the possibly sinister actions of his new foster brother, a Shoshone 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