Well, he's not clear on what sort of tactical error he's made, but he seems to have made one. Beleth's name is familiar, obviously, but that reaction could mean the elf hasn't heard from her in a long time and he's worried or it could mean there is discord between them that Barcus is entirely ignorant of. He's quiet for a long few moments, pale eyes searching the elf's face, trying to read him.

"The problem with that," he says finally, "is it's not an easy tale to believe. I'll do my best, though. I've no reason to lie."

"My name is Barcus Wroot. I'm a deep gnome from another world entirely, called Toril. You won't have seen my kind before. But Beleth and myself and, mm, quite a lot of others, were brought into a place called Caldera, via magical rifts."

(Should he mention Solas is there? Probably not, but he might have to, to fully round out the explanation.)

"The leadership of Caldera wanted help in saving the place from..." he gestures vaguely with one hand. "Honestly, we're not clear on the full extent or cause for what's going wrong. Twists in the local magic, weird monsters, that sort of thing. It's a work in progress."

"I met Beleth when she first arrived. She was considering one of the underwater quests and I gave her some flares to assist. She was interested in how they're made, the chemical reaction that allows them to give light underwater."