Well for marketing purposes, DC Comics did not give enough preview pages of Batman #13. Boo, DC Comics you suck! However, Dark Knight News has been collecting Greg Capullo’s (artist of Batman) sketches of Batman #13 just for this reason.
Warning: some sketches found may or may not be for Issue #13. Due to Capullo’s ambiguous tweeting, he might have leaked different sketches for different issues.
The first set of these sketches is of Bruce as Batman talking to Alfred. I’m guessing Bruce is discussing the Joker’s disappearance from Gotham City with Alfred. Here’s a few images of this discussion brought to you by Greg Capullo.