...the villains would be Bane, working under Hugo Strange. Bane would be played by Tom Hardy, and his origins would be pretty much the same as in the comics. His dad was a revolutionary who was killed, and Bane as a small child would be thrown in prison in his place. Having to face a life sentence at such a young age would take a tole on his mind, and he ends up under the care of psychiatrist Hugo Strange.

Strange (played by Paul Giamatti) introduces Bane to the supplement that gives him his super-human strength, to study its effects on a human being. In this, Bane wouldn't have the tubes of Venom, but it'd be more of a steroids type thing.

Bane starts to use the supplement, and starts to become stronger, faster, and more agile. Strange trains him to be an amazing fighter, and when he decides Bane is ready, he puts him on the streets.

This is where Batman comes in. Bane starts to make a name for himself on the underbelly of Gotham, as a fighter of sorts. Batman investigates the mysterious new leading criminal.

Batman underestimates Bane's strength, and is severally injured. Maybe have a callback to the iconic "I break you" comic panel. After the fight, Batman is so injured he can barely move. Bane stands over his body, ready to finish him off, when Strange appears from the shadows, and tells him to hold off. They take off his mask, and Strange immediately recognizes him as Bruce Wayne.

They take him to the hospital, but let no one know who he is.

That's just about the first half hour or so, and I can't really think much right now. But, I think that'd be a pretty awesome movie right there.