The boy puts the potion into the soup, which the Grand High Witch has requested be prepared garlic-free. All the witches except the Grand High Witch eat the soup and turn into rats. Mr. Stringer and his staff try to kill the witch-rats.
The grandmother and the three kids have a final confrontation with the evil Grand High Witch in her room. When the demon tries to kill the grandmother, the kids spring mouse traps on the Grand High Witchs only toes, and force her to swallow the potion. She turns into an enraged rat and tries to kill the kids, but the grandmother traps her under a water jug. They decide to take the Grand High Witchs money trunk and potion bottles while the Grand High Witch threatens to get them for this. When Bruno sticks his tongue out at her, the Grand High Witch angrily calls him a filthy sewer guttersnipe. One of her threats is to poke out the kids beady eyes.
The grandmother releases the Grand High Witchs cat Hades, who was locked in a cage by the Grand High Witch. While the demon-rat pleads for mercy, Hades knocks over the water jug and kills the Grand High Witch. Daisy/Mary and Bruno go to live with the boy and his grandmother and plan to turn all witches into rats in order to free the world from the plague of evil demon witches forever.