they are both nazi german guards, they are watching the Fence. They can't let any allies or spies inside. The SS Officer always tells them what to do and Hans thinks it's annoying. Meanwhile Müller wants the american ezio [who is a friend of the SS Officer] dead, becouse he doesn't likes Americans.
Hans: "Hans bewache das Tor meh meh meh" der Offizier geht mir auf den Sack, ich will doch nur in ruhe meinen Bier trinken.
Müller: und ich mag diesen Ezio nicht.. wir sollten ihn töten..