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.
You see from the Batman #13 preview on USA Today, Gordon looks horrified as he sees a figure standing at the threshold of the GCPD. Gordon says “No, not you.” The end, but DKN has more from this scene down below. You will see the horror in his eyes and the silent screaming in the images below of Gordon.