Then he heard one of the Investigators, the sound it made with its stainless steel treads on the concrete floor. It came crawling out of the dark with its thermite-tipped scorpion sting cocked back low. The chassis had started out fifty years earlier as a remote-manipulator intended to handle toxic spills or nuke-plant cleanups. Slick had found three unassembled units in Newark and traded a Volkswagen for them.