Plot

The Peanuts gang is involved in a variety of activities, including a baseball game and a school field trip.

- Peppermint Patty's father would like to send her to a Private School, but she's concerned about how much they would cost. When she tells her concerns to Snoopy, he provides her with a brochure to a place called The Ace Obedience School ("Complete training: $25"). Patty decides to enroll, but grows rather curious that almost all the 'students' have dogs. Classes consist of Patty spending a whole day learning how to sit, and jumping hurdles.

After several weeks, Patty receives a diploma. Figuring school is over, she figures her troubles are over, but at school, Marcie tells her that their teacher doesn't believe her. Patty then gets Snoopy as her attorney, and shows her diploma to the Principal. However, when she finds out she has graduated from "A Dog School," she goes looking for Snoopy.

Unable to find him, she sees World War II (aka The Cat Who Lives Next Door), and assumes it's Snoopy in a cat suit. Snoopy soon enters the fray and rescues her, causing Patty to apologize for her planned actions.

- Lucy attempts to be romantic towards Schroeder, but he rebuffs all her advances. Claiming his piano is 'too much competition,' Lucy snatches it away, and throws it down a nearby sewer. Charlie attempts to help Schroeder get his piano back, but a rain storm carries the piano down the sewer and out into the nearby river. In the aftermath, Schroeder decides to order a new piano.

- While playing baseball, Marcie soon becomes obsessed with the thought that Peppermint Patty's team needs baseball caps. Patty tells Marcie they don't need caps, but eventually, gives into Marcie's request to have her make caps (each one never seeming to be made right).

Patty thinks she has found her solution when the local baseball team has a kids day with a one-cap-per-kid promotion. Patty attempts to get nine caps, but decides not to when she falls over a wall.

- While playing a baseball game, Charlie Brown claims he's feeling woozy, and goes home. However, he instead goes to the hospital for a check-up. Though he has no idea what his condition is, after being examined, he's placed in a hospital bed.

Peppermint Patty and Marcie attempt to visit him, but are turned away because they are too young. They then decide to sit on a park bench across from the hospital, hoping their presence will help Charlie get better.

Meanwhile, Lucy grows concerned for Charlie Brown's health. When after some time it seems his condition has not improved, she promises that if he gets well, she won't pull the football away again.

Shortly afterwards, Charlie appears at her door, ready to have her make good on her promise. Linus tells Charlie that he can't trust his sister, but Charlie is sure she's being truthful. However, when he goes to kick the ball, he ends up kicking Lucy's hand instead.