In the sixth adventure of a seven-book series beginning with Mister Monday (2003), Arthur tries to hide his powers, his identity, and his body’s gradual shift toward immortality as he explores the enormous, fantastically constructed House in search of the Sixth Key. Loyal to his friends yet driven by the urgency of his quest, he relentlessly pursues his goal. The cliff-hanger ending will leave fans hungry for the final volume in this fast-paced adventure series. The complex, imaginative framework story of the Keys to the Kingdom series will confound those who have not read the earlier books.