Amazon.com Review:
By Amanda Richards

During a break in faerie activity, the children try to get on with their lives. Mallory throws herself into her fencing, Simon looks after his animals and Jared continues to get into trouble.

But this peace and relative quiet doesn't last long when a shape changer appears at a fencing match, and contrives to get Jared into even more serious trouble than normal.

The plot thickens when Mallory disappears, and they have to pursue her into the depths of dwarf territory, solving a tricky riddle as they go along. The dwarves want the Field Guide really badly, and as the twins don't have it anymore, they have to ad-lib to the best of their ability.

After a tour of the dwarf realm of undying beauty, they meet with the dwarf Lord Korting, and see their sister under glass doing a Sleeping Beauty imitation. By keeping their wits about them they escape captivity and tough puppies, and witness a brutal betrayal by their enemy Mulgarath.

This is the darkest of the series so far, but one of the most detailed. Enjoy, you've only one more to go.