Ten-year-old Leo's future and the fate of the extraordinary Whippet Hotel, where his father is the maintenance man, are at stake when a series of cryptic boxes leads Leo to hidden floors, strange puzzles, and unexpected alliances. Interest Level: 3-6 Reading Level: 5.7 ATOS Book Level: 5.7 AR Interest Level: MG AR Points: 8 AR Quiz: 146286EN Reading Counts Level: 5.6 Reading Counts Points: 12 Lexile Measure: 870.