Harry allowed his grin to remain plastered to his face as he entered the last room on the floor. The space was a perfect circle, much smaller than the Ritual Room directly above it, and much calmer in energy. For this was for a purpose far more intimate than ritual of that sort. The room was brightly lit from a point high in the ceiling. Harry had never found the source of the light ... it was just ... there. It shone down brilliantly onto a large bluestone standing stone at the centre of the circle, drenching it in a beam of the fiercest white glow. It had been placed there by Merlin himself, to allow him to commune with the other wizards and his giants, when they were building his great ritual circle at Stonehenge ... the single most powerful monolithic stone circle for ritual magic ever built anywhere in the known world or beyond.