One day Amy throws a tantrum when she finds out that Meg and Jo are going to the theater with Laurie. Amy wants to see the show and demands to come along. Meg wants to let her, but Jo says she cannot. Jo shouts at Amy and leaves in a huff.

When the older girls return, Amy looks oddly triumphant. Jo knows that her sister can be quite vengeful and nervously waits to find out what she has done. After dinner, Jo goes to work on a little book of stories she has been writing for several years—but she cannot find it. She thinks Amy hid it, but in fact the situation is far worse: Amy burned it.

Jo smacks Amy and swears never to forgive her. Eventually Marmee finds out, and she explains to Amy how terrible it was to destroy her sister’s work. This makes Amy feel guilty, and she apologizes. Jo refuses to forgive her. Even when Marmee intervenes and asks Jo to put the matter behind her, Jo says she will not.

The next day, Amy is beginning to feel wronged again. She has tried to make up, but her sister is giving her no help. When Jo and Laurie go off to ice skate together, she grabs her own skates and follows. Jo spots her sister but refuses to talk to her. Laurie checks the ice and says it is only safe at the edges of the river, not in the middle. Jo does not know if Amy has heard this warning, but she skates away without passing it on.

As it turns out, Amy did not hear. As soon as she gets her laces tied, she skates toward the smooth, thin ice at the middle of the river and falls through. Jo stares in horror, and Laurie rushes to the rescue. Eventually Jo shakes herself into action and helps rescue her sister.

Back at home, it soon becomes clear that Amy is frightened but otherwise unharmed. She falls asleep by the fire, and Jo tearfully tells Marmee what happened. She blames her terrible temper:

It seems as if I could do anything when I’m in a passion; I get so savage, I could hurt anyone and enjoy it. I’m afraid I shall do something dreadful someday, and spoil my life, and make everybody hate me.

To Jo’s surprise, Marmee says that she used to have exactly that same sort of temper and that she has worked hard to learn to control it. She asks Jo to remember this day forever and to use the memory to keep herself calm when she feels anger taking over. Jo feels inspired to learn to master her anger. Soon Amy wakes, and the sisters tearfully forgive each other.