It looks to me like the two people with the greatest clue here are Klaus and Tarvek. Klaus looks grim. Tarvek looks like he's having the sort of revelation that will precede grabbing Agatha and running like hell.

In chess terms I suspect Tarvek has just noticed Agatha is "in check" from at least two different angles, and he has precisely one move to literally "castle" her out of the way before the game ends abruptly and messily.

All pure supposition of course.