A foul-mouthed curse echoed in the eerie darkness of the night-time cathedral illuminated only by the moon and a solitary taper in the hand of the blasphemer. He had stubbed his toe against a stone lying in the under-construction nave. The intruder whispered to himself, “Loudmouthed fool! You’ll give yourself away if you go on like that!” Learning from experience, he kept his eyes on the ground and avoided further pain to his feet or worse, tripping and causing himself a serious injury. Anyway, he did not have far to walk, the wooden scaffolding rose above him, where the labourers were raising stone for the new northern wall. Tilting his candle carefully so that the molten wax fell on a flat rock, he quickly worked the taper into the pool of wax before it set, thus fixing it upright. He