El libro prohibido de Exe

Mike and Akela can't contain their curiosity any longer and will do anything to uncover his secret. But there's no way... Exe is so obsessed with hiding it that he even keeps it in a safe with four locks. Each one is hidden behind a series of incredibly difficult tests that they'll have to overcome if they want to open it: Skill Concentration and Memory Speed Strength and Balance Exe is sure that Mike and Akela won't be able to complete the challenge... Will you lend them a hand? Get all the keys and discover the best-kept secret in the Exe book!