Use Batman's Cryptographic Sequencer and track down the XY coordinates 700, 490. You'll intercept a radio frequency that reads the following numbers: 9-23-9-12-12-18-5-20-21-18-14-2-1-20-13-1-14 (it will then make a buzz sound and repeat these numbers) When matched to the corresponding letters of the alphabet they spell out I WILL RETURN BATMAN.