Istredd turns to look at her, noting that she did seem to freeze, and she's tense. He may be very oblivious at times, but he can read body language. At first he is very confused, but when she says she's heard a story like it, he pauses as well. For a moment they are probably both tense, staring at each other, his gaze moving from curious to focused. Could they be from the same world? There is Geralt and Yennefer. It would be like Geralt not to mention there is someone else there, so he wouldn't expect that anyway.

"Yes. They're not scars, they're conduits to other worlds. They can be used to teleport creatures from other spheres to ours. I saw it happen with my own eyes."

The ground rumbles under them again but that is beside the point right then.

"I was with a witcher named Geralt." Istredd tilts his head at her. "Do you ... know him?"