Susan and Colin, temporarily separated from their parents, stumble onto magical doings on Alderley Edge, a wooded ridge six hundred feet high and three miles long that towers above the surrounding countryside in rural Cheshire, author Garner's home ground. Its weather, landmarks, woods, caves, tunnels, lakes, and moors are a major presence in the story, and Garner makes the landscape come alive.

In Garner's hands Alderley Edge becomes the ideal setting for fantastic deeds. The Edge is honeycombed with the abandoned shafts and tunnels of human miners. Beneath these are the forgotten shafts of dwarves that connect with the human mines and the surface in surprising ways. One ancient network of tunnels is overseen by Cadellin, a wizard guarding one hundred and forty silver-clad knights from the world's youth. Another is the home of the "svarts," a nasty tribe of goblins in uneasy alliance with the morthbrood, a...