Return to Lost City — Scott Ciencin

Young Andrew and Lian pay a return visit to their old friends in Lost City, a place that served for years as the secret home of a noble tribe of Troodon knights. When they arrive, they find that an elder Troodon has gone off on a crazy, Don Quixote-like quest to prove he's still a great champion. Now it's up to Andrew, Lian, and their Troodon friend Arri to find this old knight and bring him back before he wreaks havoc in Dinotopia. But they may find out that his quest is not so crazy after all--and that the lives of an entire saurian race may hang in the balance. Set in the world created in James Gurney's bestselling illustrated fantasy books, Return to Lost City is an imaginative story of courage, friendship, and adventure.