Zhackie hasn't been himself since that encounter in Oasis. He was anxious, jumpy, being seconds away from death really has a way of making people more, careful. He was sleeping even less, he's lost his appetite, his usual free spirited and witty persona was slowly being replaced by one of caution and apprehension. When he realized this, he knew that encounter had taken something from him, and whatever it was he was determined to get it back. That's when he went into Pinkerton office and said "Give me the most dangerous bounty you got". That's when he strode to the sewers alone, in search of his mark. ((Got it now?))