Wait until she runs into him pretending to be a vapid playboy. That'll go over well.

Fortunately (for everyone) there isn't much call for that, here.

He can tell her, or he can show her. In the end, he opts for showing and simply heads the direction of the door. "As far as I can tell, this world has been destroyed. The only life I've seen outside the walls that surround this building are dead."

He realizes that sounds insane, does he get points for knowing when he sounds nuts?