Batman remained silent as he followed Jason to the apartment building. He was more than wary. But he couldn't risk Jason killing anyone. He had to save Jason. Though it would no doubt be anything but easy. As they walked, Bruce remained quiet for a while. Hearing what Jason said, he sighed. "I do miss this. The old days between us when you were Robin." Before you started killing after I failed you. Batman wanted to say those words but for now he didn't. He couldn't.
Seeing the building, Bruce frowned but stayed quiet. He wasn't sure what his former ward was up to but it would no doubt involve him trying to get Batman to kill. And Bruce wouldn't. It would probably frustrate and piss Jason off but what other choice did Batman have? If he began killing, he became like the criminals he fought.