Sixteen lines stretching into infinity find a moment of confluence here. Two parallel lines imply a plane; four orthogonal planes, a tube. Four tubes approach and part ways, each a connection between the open sky and the earth underneath.
Within the slipping folds and turbulence of their mutual passage, a space is hidden. Its presence is shielded from the senses by the overwhelming Platonic clarity of the tubular volumes. Four tubes form four rooms, two of which sacrifice of themselves in their mutual collision. Mental arithmetic of this subtraction is confounded as the visitor circulates from one extremity of the structure, through the interior knot of the building, to the opposite extremity.
If the visitor were to stumble upon the hidden room, she would find something that no other space in the structure offers: access to the surface of the earth, to the physical boundary between above and below.