Mister Monday

Saved from an early death by an unusual key, Arthur has no choice but to escape to a secluded house when the vengeful Mister Monday hunts him to get that key back. The strange part? Arthur is the only person who can see the house he hides in. If your child likes tales of magic, he'll love the first book in this suspenseful fantasy series.
Seven days. Seven keys. Seven virtues. Seven sins. One mysterious house is the doorway to a very mysterious world -- where one boy is about to venture and unlock a number of fantastical secrets. This is another thrilling, triumphantly imaginative series from Garth Nix, the best-selling author of The Seventh Tower, Sabriel, and Lirael.