Charlie Brown, Sally, Linus, and their friend Janice board the schoolbus for another morning trip to school. As Janice gets on the bus, she bumps her arm, claiming she has another bruise. On the bus, she tells Linus that she has been noticing a number of bruises on her arms and legs.
Later on at school, Janice complains about feeling tired. After Linus feels her forehead, he suggests she go to the school nurse. As class continues, Linus sees Janice being picked up by her Mother outside the school.
Several days pass, and Janice has not returned to class. Shortly thereafter, the teacher tells the class that Janice is in the hospital.
Linus and Charlie Brown stop by after school and visit her. Though what Linus originally thought was just a fever, is something completely different than what he was expecting. Janice tells the two that she has been diagnosed with Leukemia, which explains the bruises on her body. As Linus and Charlie Brown question her symptoms, Janice explains about the different tests she took before they gave her diagnosis, as well as chemo-therapy. Though Janice says it is supposed to make her better, it makes her hair fall out, and her stomach feel sick.
As winter comes along, Janice returns to school, but as she has lost her hair, she has to wear a hat. Linus tells how he was hoping to push her on the swings at school, but due to winter, they have been taken down. As they talk, a nearby boy makes fun of Janice's hat and knocks it off. Seeing Janice with no hair, he makes fun of her, before Linus angrily explains what has happened to her. The boy apologizes, and returns her hat.
Sometime afterwards, Linus decides to give Janice a little present, and goes to her house. He is met at the door by her two younger sisters, who explain that she is off getting another treatment. Even so, one of them does mention that Janice seems to get lots of presents, and her condition is very delicate, so much that they can't get sick, otherwise it would be bad for her.
Eventually, Spring comes around, and Janice returns to school wearing her cap. With the swings put back up, she asks Linus to push her on them. As she does, her hat falls off, and we see her hair has grown back, a sign that she has beaten her cancer battle, as Linus cheers happily.