With only a few days before their high-school graduation, it looks like airheaded rock star wannabes Bill (Alex Winter) and Ted (Keanu Reeves) are doomed to flunk all their finals. The boys' long-suffering teacher (Bernie Casey) gives them one more chance. If they can ace an oral exam on the topic of how a famous historical personality might react to modern times, they will be allowed to pass. If not, Ted's dad will plunk the boy into military school, thereby breaking up the boys' garage band permanently. Bill and Ted receive unexpected aid from a very unexpected source: Rufus (George Carlin), an Emissary from the Future. It seems that in Rufus' time, Bill and Ted's rock music is the basis of all society-and if their band is aborted, Rufus' world will no longer exist. Thus, Bill and Ted are whisked off in a time machine (actually a telephone booth) to retrieve a few historical characters--including Joan of Arc, Abe Lincoln, Napoleon and Beethoven--as "eyewitnesses" for their crucial oral exam. Bill & Ted's Excellent Adventure inspired both a sequel (Bill & Ted's Bogus Journey) and a Saturday morning cartoon series.