The Nekross explain that when Helen died fighting their probe ray they extracted part of her DNA in order to synthesize clones and recreate her magic. However Helen casts a spell allowing her and the boys to escape home. Randal gives her an amulet which restores her memory but she and Ursula know this cannot last and,after the family has returned to the factory and used magic to destroy the Nekross cloning factories around the world, sending the aliens back to their planet, Helen disappears again,happy in the knowledge that her son will be a powerful wizard.
—don @ minifie-1