Bill & Ted give a free Wyld Stallyns concert in the park, only to be totally walked out on. This depresses them to the point they decide not to continue trying to be musicians. In the future San Dimas, the Three Most Important People summon Rufus and explain what has happened, saying that their future is on shaky ground. If Bill & Ted do not continue to try to create their music, life as they know it will cease to happen and time has started running backwards. They tell Rufus that he must not tell them about what is happening to the future, he must instead show them that they need to keep trying. Rufus drops in on the dudes, slightly younger and his hair longer. He realizes that he will continue to get younger until Bill & Ted decide to go back to music, and so he asks them to help him with an unspecific problem, giving them an itinerary they are supposed to follow. Their first stop is at Thomas Edison's laboratory. They find Edison trying to perfect his phonograph, but having no luck. Bill & Ted encourage Edison not to give up, and Ted accidentally knocks one of the inventor's stale pancakes (he hadn't felt like eating in a while), which inspires Edison to pound his cylinder flat and make a record instead. Returning to the booth, they find Rufus has turned into a geeky teenager. They continue to follow the itinerary Rufus gave them and end up in the workshop of Leonardo DaVinci, who is working on his spiny-winged-up-and-down-flying-thingy without much success. Rufus turns nine years old and starts running amok in the inventor's workplace. Young Rufus insists he can build Leonardo's flying thingy and proceeds to make one out of the phone booth. It succeeds in flying, for a little bit, but it inspires Leonardo to keep trying. Not sure they're reading their next destination correctly, they take a chance and end up in the lab of Joseph Priestley, who had just discovered how to carbonate water. Rufus becomes an even younger kid and starts mixing chemicals together, managing to mix some cherry jam in with the soda, making the first soft drink. Joseph Priestley is inspired to start working right away on diet soft drinks. Their next stop takes them to the docks of Spain where Christopher Columbus is trying to convince people to invest in his voyage to the new world. At this point Rufus turns into a mere infant. Bill & Ted convince Columbus to try getting a loan from the Queen (if he doesn't discover America, there will be no Columbus Day, one less school holiday). The Queen and King Ferdinand give him the money just to get rid of him. Returning to San Dimas, Bill & Ted realize they have found the inspiration from the historical figures they have met to continue trying to make it as Wyld Stallyns, which restores Rufus to his former self and puts the future right again.