Part fantasy, part mystery, part allegory, and part myth - author Patrick Carman covers all the bases in his young adult novel Floors. That's a high hurdle for any book to leap, and I think Floors clears it with room(s) to spare.
Every labyrinth needs a mythical monster, and in the case of the Whippet, that monster is the unnamed, unseen Mr. M. Or is it? There is a real monster inside the Hotel, and it is up to Leo to uncover it. In the process he discovers how the hotel and its builder are linked, and how Leo himself is part of the puzzle.
It's a journey of discovery for both Leo and the reader, "Floors" is a highly enjoyable story on many levels.