What will you do next?
"Okay, hold up here. Why exactly do you want to kill me? Cause all I wanted to do was walk through the damn gate. Long night, huh? Bored with guard duty? Let me see the bowgun, then. Are you good with that thing?"... etc, etc, till he gets close enough that I can reach over, on the pretense of admiring the weapon, and then slip a knife to his throat.
Then he'll open the gate and do whatever the hell I want him to.