Roommates Jesse and Chester, both who have more than just a few cards short of a full deck, are stoner dudes who don't even do their jobs as pizza delivery guys well. They awaken one morning having little recollection of what they did the previous night, due to being wasted. They discover that their kitchen is full of prepackaged pudding, how they got all the pudding they are unaware. From a telephone message they receive, they come to the realization that at some point during the previous night they were at a party at the house of their girlfriends, twins Wanda and Wilma, and that today is their one year anniversary, which they did remember as they already bought the twins gifts. But the worst thing in not remembering what happened last night is that Jesse's car is missing. In trying to find out what happened to the car, they believe they have to recreate the feeling and mindset of last night, meaning getting wasted all over again. In trying to find the car, they, being the types that area easily distracted, get sidetracked by one item after another, most specifically the potential of having sex with hot babes (sex with which Wanda and Wilma have not yet provided them), and learning that they apparently had a suitcase filled with $200,000 last night, the suitcase and therefore the money to which they don't know what happened. During their day of discovery, they also end up encountering one group of alien wannabes, and two groups of actual aliens, all three groups who are after the continuum transfunctioner which they believe Jesse and Chester have. Jesse and Chester don't know where it is let alone what it is, but these three groups seem to be willing to do whatever necessary to get it from Jesse and Chester. In the process, Jesse and Chester may have to make decisions which may not only save their lives and those of Wanda, Wilma and their best friend Nelson, a zen-master, but that of the entire universe. But most importantly, they may actually find Jesse's car after all is said and done.