Balthazar's annoyed-face develops a bemused edge as the strange boy continues to look deeply upset. His first thought is, of course, drugs. Kids these days, right?

He follows the gesture toward Horvath and starts to moves forward, either to calm or usher the boy out...and then the glint of Merlin's ring catches his eye.

The penny drops.

Dave will get time to count to ten and then some, because Balthazar's reaction is suddenly a close match for his. Oh god what just happened...

Very slowly, he sets the antlers on the counter and takes a couple steps closer to Dave, as if approaching a wild animal. Then he ruins the effect by making a grab for his wrist.