On a white-water rafting trip, Declan is thrown from a raft and ends up miles downstream, badly hurt with a broken leg. Luck is on his side, however, as a kindly old man named Dr. Nader discovers him and takes him to Camp Sanopi, a secluded retreat deep in the woods. But Declan soon discovers that this blissful camp is not what it seems to be and that although all are welcome, none can leave.

When two students in Declan's anthropology class exhibit uncanny similarities, Declan becomes curious when both adopted young men turn out to share the same birth date, the same mannerisms, tastes, and test answers, but a blood test determines that they aren't related. When one of them becomes ill, the mystery of what brought them together intensifies. Meanwhile, Declan and Peggy discover they share a coincidence as well.