Calvin is reading his homework. Suddenly, he flies up into the ceiling. BAM! Mom yells in from the other room for him to quit banging around.

Calvin is sitting on the ceiling. Nothing else fell up, just him. If he tries to jump to the floor, he lands back on the ceiling. His personal gravity must have reversed polarity. As he walks along the ceiling, he says you'd think this would be the type of thing they'd learn about in science class. But instead, they learn about cirrus clouds.

Calvin can't figure out how to get to the floor with his personal gravity polarity reversed. There's nothing on the ceiling he can climb to get there. He wonders how he'll do his homework if he's trapped on the ceiling. Calvin smiles.

Calvin knows Mom and Dad won't be happy about things. Dad will have to bolt his bed to the ceiling, and Mom will have to stand on a step ladder to serve dinner. He'll have to hold the plate upside down and scrape the food off the underside. If he spills anything, it will fall ten feet to the floor. He says this will be the most fun he's ever had.

With all the open ceiling space, Calvin wishes he could get his roller skates. He decides to try climbing down the bookcase and jumping to a chair. Then he can pull himself across other pieces of furniture to get to his toy chest. As he walks down the bookcase, he says he can hear Mom wondering how he got sneaker prints on the underside of each shelf.

Calvin is ready to jump to the chair. He leaps. The chair pushes over and lands on its back. WHAM! Mom yells in from the other room for him to quit banging around.

Calvin tries to pull the chair upright. Mom comes over and asks if he's getting any homework done, or if he's just ruining furniture. Calvin replies that maybe he's hanging on the chair for dear life.

As Mom picks Calvin up, he tells her his personal gravity reversed its polarity. As Mom carries him up the stairs, he tells her he's been stuck on the ceiling. He couldn't do his homework there. He tells Mom she should be glad it didn't happen outside or he would be sailing through the ionosphere. As Mom puts him in his chair, she tells him she doesn't want to hear any more of his nonsense until he's through with his homework. Calvin tells her not to let him go.

Calvin declares a miracle. His personal gravity is back to normal. Mom's glad to hear it. Calvin says it's a relief to be pulled down instead of up. Mom says she'll check on his progress in a little bit. Calvin sits grumpily looking at his homework. He starts to get larger. He says "uh oh".

Calvin keeps growing. He tries to get out his bedroom door. He squeezes out into the hallway. As he crawls along, he says this has been a most peculiar afternoon.

Calvin has to get outside before he grows bigger. He barely gets his foot out the door. Once outside, he walks off saying he should get his pituitary gland checked.

Calvin runs toward downtown to find Dad at work. He figures he can help. As Calvin walks among the skyscrapers, he can't tell which one Dad works in. He decides maybe Dad can find him.

The ever-growing Calvin walks off the shore into the ocean. His head enters the clouds. He grows up through the clouds. Calvin looks up toward the heavens.

Calvin continues to grow. He gets so big he can barely stand on the earth. He gets bigger and eventually falls off the earth.

Calvin falls into the Milky Way galaxy. He tumbles around. He sees a door.

Calvin opens the door, and he's normal size in his room. He sits back down at the desk. Mom comes in and asks how his math is coming along. Calvin says he's almost started.

Mom is talking to Calvin, but he's thinking about getting another "discussion" about his study habits and the importance of homework. Calvin continues thinking about how he tried to tell her it's hard to study when one's size suddenly starts increasing. Mom is still talking and gesturing, but Calvin continues thinking about how she says it's all his fault. Mom hasn't been as big as a galaxy, so she doesn't understand how anyone else can be. Calvin thinks Mom is wrapping up, so he starts nodding. Mom tells him she's glad they had this little talk.

Calvin tells Hobbes he missed the show. He tells him he got a big lecture because he got stuck on the ceiling and then grew so big he fell off the planet when he should have been doing math. Hobbes doesn't think that isn't fair. Calvin asks for help on his homework. Hobbes says tigers are good at math. He asks what the little horizontal lines mean. Calvin tells him it's a minus sign. He tells Hobbes to let him know when he's done. Calvin is going to be reading comic books.