((The sun dawns on Gotham City; it is about 5 AM. I hope you don't mind if I speed two up, Batman and Robin))
Batman and Robin snuck to the back of the Casino, and found where the Riddler must have entered. They followed his path, eventually winding up right above the Casino vault.
The two jumped down through the hole, and saw the Riddler. But, to their surprise, surrounding the Riddler, his goons, and all the money they had gathered up, was a screen of unbreakable glass.
"Hello, Batman," the Riddler welcomed them sarcastically. "I see you solved my riddle, only to find that you can't stop me! Hahahahaha!"