In this fifth novel of the Keys to the Kingdom series, Arthur, heir to the Architect, sets out to capture the fifth key, held by Lady Friday. He gets lured into Friday's Trap by believing that she really has abdicated the Key to whoever can get there first. But, as Arthur soon realises, she hasn't really abdicated, and he must defeat her himself.
This is a good novel overall, but I wouldn't say it was great. It didn't seem to live upto Garth Nix's standards recently; for a beter read try his Old Kingdom Series. Overall, however, it was still a rather likeable book!