Suspense fiction. Adventure and adventurers -- Fiction. Spy stories.

Spy stories. Families -- Juvenile fiction. Revenge -- Juvenile fiction. Young women -- Juvenile fiction. Friendship -- Juvenile fiction.

Telegraph -- Europe -- Juvenile fiction. Boarding schools -- Europe -- Juvenile fiction. World War, 1914-1918 -- Juvenile fiction. Cipher and telegraph codes -- Juvenile fiction. Spy stories.

World War, 1939-1945 -- Germany -- Juvenile fiction. Espionage, British -- Germany -- Juvenile fiction. Diplomatic and consular service, Irish -- Germany -- Juvenile fiction. Irish -- Germany -- Juvenile fiction. Jet planes -- Germany -- History -- Juvenile fiction.

Books and reading -- Juvenile fiction. Libraries -- Juvenile fiction. Magic -- Juvenile fiction. Locks and keys -- Juvenile fiction. Best friends -- Juvenile fiction.

Spy stories. Computer games -- Juvenile fiction. Adventure and adventurers -- Juvenile fiction. Children's stories. Zac, Power (Fictitious character) -- Juvenile fiction.