Bill arrives and helps Chris move the bed so that he can physically scan the area where it was, marking the legs with books. When this proves fruitless, Bill examines the wall behind the bed. His hand passes easily through the wall and to another dimension, and draws marks on the wall outlining the apparent boundary. He explains to Chris and Ruth that sometimes lines in our three dimensions end parallel with, rather than perpendicular to, the fourth dimension. He warns them that they know nothing of what's beyond this portal, and should they follow Tina into the fourth dimension, they would only become hopelessly lost as well, since it is not manifested like the third dimension.