20 Things You Didn't Know About Batman Begins

In the last scene, Commissioner Gordon tells Batman he's worried the criminals of Gotham will up their game now that the city has a guardian protecting them. He then hands Batman a calling card left at a crime scene by a new murderer in town. Bats flips it over to reveal it's a Joker Card, confirming his next adversary will be the Clown Prince of Crime.

This scene is taken directly from Frank Miller's Batman: Year One, which this film is heavily based on. In the final panel, Gordon is pondering to himself about "Somebody threatened to poison the Gotham reservoir. Calls himself the Joker. I've got a friend coming who might be able to help. Should be here any minute."

But this isn't the only Easter egg in this scene. When first-time viewers saw the Joker card, they got so excited, they didn't notice a little Easter egg. If you look at the evidence description, the card was discovered by a police officer called J. Kerr; an obvious nod to Batman's nemesis. It's a blink-and-you-miss-it moment but it's a nice touch.