26 books
Can You Destroy the Giants from the Sea?
Can You Find the Secret of the Ghostly Guardian?
Can You Destroy the Vampire of Valdah?
Can You Discover the Dark Secret which Threatens Your Very Life?
The Case of the Dancing Bees
Can You Solve the Mystery of the Reichenbach Falls?
Can You Defeat the Schemes of a Criminal Mastermind?
Can You Save the Victim of a Web of Mystery