Player A on left dead-end of a full 8-room first level finds the stairs down, Then some players move down there and to the left. At this point, player C on the right edge of the first level uses a screw this card to find another set of stairs. Some players move down and to the right. Is this legal? If so, what is the range between the two halves of the second level? Can attacks be made through the "void" and does support work from one side to another? Additionally, if a set of stairs down to the third level is found on one of the halves, does the other one become a dead-end branch with no way down?