2014-02-12
Explanation
The Joke
A woman invents time travel and immediately goes back in time to kill Hitler. This creates an unintended consequence: with so many time travelers trying to kill Hitler, the Nazis become incredibly good at fighting time travelers. By the year 3000, Hitler is the most powerful being ever, because fighting off time travelers for centuries has made him unstoppable. He conquers the galaxy. At the end, two people discuss movies, and one says a particular film is the worst movie ever. The other asks if it is because of Hitler ending the galaxy, but the critic says no -- "It's not based on a pre-existing franchise. I see your point, though."
The Humor
The comic satirizes the classic time-travel trope of "going back to kill Hitler" by taking it to its absurd logical conclusion: if everyone's first instinct with a time machine is to kill Hitler, the constant assassination attempts would only make him stronger through practice. The escalation is deliberately ridiculous -- Hitler goes from historical dictator to galactic conqueror simply because time travelers kept giving him combat experience. The final punchline swerves away from the epic sci-fi premise entirely, landing on a joke about Hollywood's obsession with franchise-based movies. Even in a universe where Hitler has conquered the galaxy, the worst thing about a movie is that it is not based on existing intellectual property.
References
The "kill Hitler with a time machine" scenario is one of the most well-known thought experiments in popular culture and science fiction, frequently discussed as the default first use of time travel. The final panel jokes about the modern film industry's reliance on sequels, reboots, and adaptations of pre-existing franchises.