Ask him what he wants.
From Create Your Own Story
"What do you want, Dap?" You ask, keeping a cool head.
"Oh, not much. I've determined that I want your help." He looks around your living room, grabbing at a rather precious vase and examining it, before dropping it shortly after, shattering it to pieces.
"With what?" Once again you try to keep your patience, but you're getting angry.
"I want to kill the city watchman." he says with an arrogant smirk.