"Then we'll speak quickly," Damian returned. At the moment, time didn't seem to be of the essence but the depth of knowledge had to discuss was practically cumbersome. The portal was the pressing matter but the history of this world could prove vital as well. Assuming things would be similar was not a pitfall Damian wanted to fall in.
However, Gotham would be a more suitable venue. The cave in particular would be telling. The mementos on display all had history. Still, there was no reason to delay the conversation.
"We might as well start with the basics," Damian suggested. "How long you've been Batman. How long we've known each other." Establish a baseline.