 When her bike is later found near the Potomac River upstream from dangerous rapids, the police assume she fell in accidentally and drowned.Only Allie's 5-year-old brother Willis knows where she went, but he has promised her to keep it secret.Meanwhile, the eminent biochemist Fergus O'Neil is recruited by the U.S. State Department, to study stolen Soviet reports from Schutz's Group 17, and investigate his activities at Villa Petrograd, by posing as a vacationer.