Jason goes pale at Bruce's confession. He's not surprised there was a Joker in Bruce's world. His world and Bruce's world share enough similarities that there wouldn't be a reason for a Joker to not exist in Bruce's world.

What disturbs Jason instead is how the Joker still somehow came back after so many years and managed to ambush Bruce. From the way Bruce tells it, the Joker died in a way that wasn't ambiguous. Maybe there was even a body as proof. And yet still, the Joker found a way again. The bastard was like a roach in nuclear holocaust.

"The kid managed to antidote you?" He asks quietly. He doesn't know Terry but at that moment, he was immensely grateful to him being around for Bruce.