Calvin wants to know if Hobbes wants to go time traveling with him. He has built a time machine. It's a box with "time machine" written on the side. Hobbes says it looks like his transmogrifier. Calvin says it does "to the inattentive, brainless layman". He points out that you crawl in the bottom of the transmogrifier, whereas you crawl in the top of the time machine.

Hobbes asks whether they're going to the past or the future. Calvin weighs the choices. If he goes to the past, he can ace some history tests at school. If they go to the future, they can swipe something to bring back. They'll claim they invented it and be rich. Off to the future they go. Calvin figures he can hire someone to take his tests when he's rich.

Calvin tells Hobbes to put on his goggles, and they'll be ready to go. Hobbes wants to know why he needs goggles. Calvin explains time travel is not like driving down the street. There are vortexes and light speeds to contend with. Anything could go wrong. Of course they need goggles. Hobbes tries to get out by saying his goggles are in the bedroom. He tells Calvin to leave without him if he isn't back in a couple minutes. Calvin tells him to sit down. He has Hobbes' goggles.

Calvin pushes the button and off they go. Up, up and away. They approach light speed. Hobbes has to go to the bathroom. Now? Calvin can't believe it. He tells Hobbes they're in hyperspace. Is Hobbes crazy?

Hobbes wonders what year in the future they'll land. Calvin thinks it will be around the turn of the century. Hobbes hopes the earth is still around then, he's gotten attached to it. Calvin says if it isn't, he's going back to the present to see if Dad will give him his college tuition early in cash.

They're coming in for a landing. They look around. So this is the future. It looks like they're on a tropical beach. Hobbes pictured more buildings. Calvin guesses they may have landed in an arboretum.

Calvin climbs out of his time machine. They're going to look around. They'll probably run into a robot or something. Hobbes picks up something egg-shaped. Calvin thinks it's some type of transportation pod. Hobbes can't figure out how to get in it. Calvin notices there are no numbers or doors on it. As Calvin ponders the peculiar item, Hobbes asks if Calvin has ever seen a tree this color. He's looking at what appears to be a giant leg.

Calvin admits the future looks a bit different from what he expected. Hobbes says the breeze is hot and muggy. He thought they'd have figured out a way to control weather by now. Calvin says the air stinks, too. Calvin asks if Hobbes has ever felt like he's being monitored. Hobbes adds "or that you're about to do a double-take". Behind them is the face of a dinosaur looking at them.

They see a huge brachiosaur standing behind them. Off they run to the time machine. Calvin suggests they must have gone backward in time instead of forward. Hobbes asks if it was the dinosaur that tipped him off. They jump into the time machine, and Calvin tells Hobbes to face the other way to they go forward in time instead of backward. Hobbes asks Calvin if the reason they went back in time was because they were facing the wrong way. Calvin shouts back that he doesn't have a Triple-A map. He suggests maybe Hobbes would like to steer.

They're now flying forward in time. Calvin sees they're approaching the present. He asks if Hobbes wants to go forward in time like they planned, or did he want to stop. Hobbes has had enough time traveling. He opts for home. Calvin tries to convince Hobbes to go a little into the future to see what Calvin is like as a teenager. Hobbes doesn't want any part of that.

Mom is gardening when Calvin comes over and tells her he and Hobbes went time traveling to the Jurassic period today. She asks what it was like. Calvin tells her it was scary, and they almost got eaten by a dinosaur. Calvin admits they were trying to go to the future, but made a mistake. Mom is glad he made it back. Hobbes is surprised that didn't faze Mom at all. Calvin reminds him that she didn't take the frogs in the toilet.