Frowning does seem to be a likely activity of someone who noticed a kidnapping while "making rounds." If it isn't her, well, extra useless vassal.

The Lord Ruler makes himself faster than he's had reason to be in a long time. He's confident a human wouldn't have time to so much as blink, but it's best to be on the safe side. He doesn't see Verve's atium ghost doing anything that looks magical, or the real Verve for that matter, so he rushes her and claps a hand over her mouth. While dragging her back toward the cave, he tries to keep her disoriented enough that she'll have less of a chance to cast something.