Peridot is scared. Maybe that's a bit of an obvious statement, since everyone here is probably scared to a certain degree, but the whole death fog thing has given her significant pause. She's shaking on the spot for most of the discussion, but Syr charging ahead spurs her to action.

"W-wait! Syrlya--!"

She dashes into the fog after him. No time to think. If she hesitates, she might try to talk herself out of it.