After the end of World War II, the parents temporarily remove fourteen-year-old Nathaniel and his older sister Rachel from London and leave them in the care of a family friend, Walter, nicknamed the Moth. Soon other characters appear in the house, who apparently were once associated with the teenagers’ parents in secret work for the secret service. They all help Nathaniel and Rachel get ahead in life. As the years go by, the parents never return…
Growing up, Nathaniel begins to notice that he is being watched. His hunches are confirmed when one night someone breaks into their house. Brother and sister manage to escape, but from now on Nathaniel is sure that their parents did not just leave them in the care of strangers. Perhaps it was a deal to keep them safe.
But what were they being protected from? Who really are the people who have cared for the children for so long? Where are their parents and why can’t the family still be reunited? To find the answers to these questions, Nathaniel returns home and plunges into a world of dangerous spy games.