Giraut Leones lives in Nou Occitan, a place where young people spend most of their time gossiping, writing poetry, and fighting duels over various insults. Eventually we find that Nou Occitan is just one of humanity's "Thousand Cultures," an artificial colony set up on a terraformed world to bring art, chivalry, and other old-fashioned values to life. Some years ago the springer, a device enabling teleportation travel, was opened, resulting in friction between the traditional dilettantes and Interstellars, youngsters who adopt new ways of life. Giraut's old friend Aimeric is called back to his home colony of Caledony to aid in the economic recession and cultural explosion that will surely follow the opening of the springer there. When Giraut is betrayed by his entendedora (part mistress, part girlfriend), he seizes the opportunity to go along as an ambassador. A Million Open Doors becomes a coming-of-age tale as Giraut adapts to a culture radically different from his own. Caledony society is colorless, repressed, money-driven; it emphasizes religion and hard work. Bewildered by the discouragement of art or pleasure, Giraut opens a college to teach Occitanian culture to interested Caledonians. The threatened religious and political leaders, of course, look on this as an oddity, if not an outright seed of revolution. During the cultural and political upheavals on Caledony, Giraut and friends learn about life, love, diplomacy, and cross-cultural friendship. The premise--human colonies flung across the universe evolving on hundreds of different planets now being transformed by instantaneous space travel--has been explored before. But John Barnes's sense of humor and world-building skills make it great fun. --Bonnie Bouman