He ignored the offered hand, straightening up on his own. "If we get lost, I am not helping you find out where we are." Which was a slightly ridiculous threat to make, between the mental link and the fact that they were in Berlin, but Prussia felt it needed to be made on general principle. It reminded him also that he'd have to work out how to keep West from reading his mind…

"I imagine I will regret this, but lead the way." And don't start any trouble!