9 in-game years-no casino

Help! I've clocked over 250 hours in my save and can't seem to activate the "mysterious Mr. Qi" quest to open the casino. The Wiki is no help, the only answers I'm seeing is that you have to put a battery pack into a box in the tunnel by the bus stop, but there's no box in the tunnel. I feel like something has to trigger the box like a secret note or something but I've been unsuccessful in finding one. I've also reached the bottom of the mines, as well as floor 100 in the skull caverns. Does anyone know how to trigger the quest??