In The Grey Walls, our heroes battle an interdimensional intruder like nothing they’ve ever seen before. Having taken over an office tower, the creature seems to be slowly absorbing its hapless victims– which include Nonstop, Krork, and all of the office workers, as well as a multitude of nightmarish creatures from other dimensions.
The result is an office tower filled with a maze of constantly-shifting gray walls– walls which bear still-living impressions of the creature’s meals.