This one-paragraph portion reveals Chief's relapse into paranoia. He imagines the fog increasing, forcing him to crawl on the floor to find the gum he hides beneath his bed. He writes that McMurphy doesn't understand that the patients only want to be safe and not let him drag them out of the fog.
Chief speaks for himself and the other patients. He perceives that a showdown will soon occur between Nurse Ratched and McMurphy, and fears that the fallout from the battle will negatively impact the other patients. In this respect, he believes that the devil he knows is better than the devil he doesn't know.