Shortly after arriving back in England, while the boy is working on the roof of the treehouse he has been building, the boy sees a strange woman in black staring up at him with an eerie smile, and he realizes that she is a witch. When the witch offers him a snake to entice him, he climbs further up the tree and stays there, not daring to come down until his grandmother comes looking for him. This persuades the boy and his grandmother to be especially wary; and he carefully scrutinizes all women to determine whether or not they might be witches.