(From the publisher):
A Hidden door. A magical staircase. Discover the World of Droon! Somebody has robbed the Lumpies' village! And it can't be Lord Sparr - because he has mysteriously disappeared. The rumor is that a terrible beast is behind the crime. So Eric, Julie, and Neal set off with Khan and Princess Keeah to find the creature. Instead they find a big surprise!
Original title: The Tower of the Elf King
Genre: Fiction→ Children & Young Adult→ Fantasy→ Fantasy Worlds