Sister Lost — Frank Buchan

Ensconced in the home of their sometime mentor, the wizard Hemming, the nine witches of Elba have grown into their magic. But the scars left by the evil Lady Dari Dyce run deep, and she has not forgiven her defeat. While Hemming wrestles with portal magic he doesn't understand, leaving the sisters to fend for themselves, Dyce and her lapdog Montague Franz are plotting evil that will test the commitment of the witches and perhaps destroy them all. This is the continuation of the story begun in The 9 Sisters.