Iks ili igrek - Kristi Agata

Amateur detectives Tommy and Tuppence solve almost the most difficult problem in their lives. In a boarding house lost on the deserted coast of England, where old ladies, retired colonels and old virgins live, they are hiding and preparing for active actions against England Nazi spies. Conventionally they are called "X" and "Igrek." Who are they? What do they look like? How do you calculate them? The most complex puzzle is supplemented by dangerous and unpredictable adventures...