This is the second book in a series of three middle reader novels that follow the adventures of Caroline and Polly, two best friends, and Polly's brother, Joey. When Caroline's family moves from Ohio to Tucson, AZ, the children finds ways to get together during summer vacations. In this book, Caroline has lived in Arizona for one year when Polly and Joey come to visit. During their time in Tucson, the children learn about desert culture and history. They have the opportunity to go to an archaeological site at Chaco Canyon being supervised by Caroline's father, Dr. James. He and his assistant, Emma, teach the children about the ancients who lived in the area thousands of years previously. When visiting an outlying site, Joey stumbles upon artifact thieves and assists in their capture. Emma takes the group to her home on the Hopi reservation where the children are exposed to traditional Hopi ways. Throughout the trip, the children learn of past migratory connections between the ancients in the Southwest, Mexico and even Ohio.