Chased by strange figures on Alderley Edge. Colin and Susan are saved by the Wizard. He takes them deep, deep into the caves of Fundindelve. There sleep a band of knights, until the hour when they must rise and fight the evil Nastrond. Guarded by the strongest magic the world has ever known, a spell so powerful no evil can ever break it... a spell whose heart is sealed with Firefrost - the Windstone.