If this grave void at the heart of Westminster had any purpose, it was like the empty chamber that made up most of a violincello. The strings, bridge, bow, and the player itself were all to the outside. Nothing moved, nothing happened in the dark cavity; yet none of it would work unless it were built around a central emptiness that held the parts in their proper relation to one another, and withstood the relentless pulling of the strings while sympathizing with their tiniest stirrings.