Tim grabbed Dick's old costume and insisted that he and Alfred go after Batman and Nightwing. They arrived in time to see Two-Face blow up the building a second time. Robin attacked Dent. He and Alfred saved Batman and Nightwing. Tim confronted Batman with his knowledge and that he'd stuck a tracking device on Dent. The three tracked him down and took him in. Back at Wayne Manor, Bruce agreed he needed a partner and decided to give Tim a shot.
Batman issues 436-442 are missing cover dates; the Grand Comic Book Database (www.comics.org) assigns this issue to "December".