Books in Pratt Twins series

Chris and Susan visit Washington, D.C., on a class trip and wind up in the midst of international intrigue, when Chris befriends Natasha, a young Russian ballerina who wishes to defect

In New Orleans for an historical research competition, twins Chris and Susan Pratt, along with their competitor, Caroline, uncover a drug smuggling operation in the French Quarter

Now graduated from high school and living in New York City, twins Chris and Susan Pratt find themselves snared in an art-smuggling scheme after a shady character buys some of Susan's paintings

While vacationing on Seagull Island, the twins get summer jobs to help pay their college expenses and become involved with the Hollingsworth family, who the girls are sure have something to do with the mysterious water pollution

Twins Chris and Susan visit their aunt in California and are asked by a Silver Screen Studio executive to keep an eye on his daughter, who has lately been acting strangely