Leareth has been watching with a neutral expression. It's a very effortful neutral expression, and a very effortful decision that now is not the time when it would help, at all, with anything, to feel the entirely appropriate and reasonable devastation that Carissa - the other Carissa, but maybe his as well - must be feeling right now.
He hasn't been reading any of their minds, even though this might be useful, because that would be one more step too difficult.
...
Oh, Carissa is talking to him now...?
"- Right," he hears himself say, distantly. "I spoke a little of it to Mhalir. The gods of Velgarth are against change - because of how They use Foresight, I think, but also the Cataclysm spooked Them, very understandably - anyway, I kept trying to fix things and everything kept failing as though by improbable poor luck, and eventually I put it together. And decided I would need to take the war to Them..."
He describes his plan, spending five sentences on the specifications for his god's values and one sentence on the cost in blood, though of course now he expects there are other avenues.