Ima's longtime boyfriend, Paul Kaminski, goes to Estonia to collaborate with scientists on his artificial heart project. When the equipment disappears, Paul asks Ima to bring a fresh set to Estonia to continue his research. Concerned about going to a Soviet Republic, Ima invites her Manhattan pal Riina Feingold to come along as interpreter because her parents had fled to New York from Estonia in 1940. As couriers of scientific equipment, the young ladies head for Tallinn, Estonia. Upon arrival, they get accused of a spy plot. Ima tries to convince customs the apparatuses they carry are not bombs. The officials seize their passports and equipment. Then, Riina's last name reminds them of a murderer who escaped in 1942. While Ima gets involved in investigating the whereabouts of the missing artificial hearts, KGB seeks to arrest Riina to use her as a bargaining chip to exchange for the return of her father to Estonia.