The story begins on a small farm in the English countryside. The story's narrator, an unnamed young girl, introduces herself and shares a little bit about her special abilities. She says that she has a "magic finger" that shoots lightning at people who make her angry. This lightning often brings about dramatic transformations.
She lives next to the Gregg family. The Greggs have a love of hunting. They go often, much to Philippa's disapproval and dismay. One day, they come home with a dead deer. This really upsets her and she gets angry with them. They do not take her criticisms seriously and make fun of her. She decides to use the magic finger on them.
She recounts a time when her teacher, Mrs. Winter, criticized her for misspelling the word "cat." She says that the teacher was zapped by the finger and sprouted whiskers and a tail. The whole class laughed at her. She adds mysteriously that the teacher was never quite the same after that. The finger, she notes, causes unexpected things.
She says that after this unfortunate occurrence she vowed never to use the finger again. Unfortunately, in the interaction with the Gregg family she becomes overwhelmed by her feelings and is not able to stop herself. She says that the same thing happened in her interaction with Mrs. Winter where she became too angry to not use her powers.
The Greggs wake up the following day and are shocked to find that their bodies have changed. They have become much smaller and their arms have become duck wings. Their home is commandeered by a group of ducks who have become human-sized. With no place to go, they make a nest in a tree and go to sleep.
The Greggs wake up the following morning and discover that several of the ducks have taken their guns and are threatening to shoot them. Desperate and panicked, the family begs to be spared. The mother duck asks why she should spare their lives when they killed her children. She makes fun of their prior love for hunting.
The Greggs agree to give up shooting and the ducks smash their guns with hammers. They promise never to harm another animal ever again. The ducks return to the lake and the Greggs go home. The Greggs transform back into their human forms.
Philippa goes to visit the Greggs and discovers that they've changed significantly. They no longer hunt or own guns. They feed and care for the birds on their land. The two young boys, Philip and William, retell the entire story to the girl. She is pleased to see this development.
In the distance, the girl hears gunshots. She surmises that it came from the direction of the farm owned by the Coopers. She feels her magic finger begin to power up. She seems to be preparing to teach them a lesson.
