In an old episode, the Planet Express staff take Fry around to see the various wonders of the universe, including its edge. Beyond it is a parallel universe, and they explain that there is only one parallel universe, not endless parallel universes. But then later in the series, there's a whole episode about parallel universes. What happened to consistency? First you say there are only two universes, and now you're running through a bunch of 'em? What the hell?
