Quote from : The Riders Book

The whole underneath of Paris was an ant nest, Metro tunnels, sewer shafts, catacombs, mines, cemeteries. She'd been down in the city of bones where skulls and femurs rose in yellowing walls. Right down there, win the square before them. through a dinky little entrance, were the Roman ruins like honeycomb. The trains went under the river. There were tunnels people had forgotten about. It was a wonder Paris stood up at all. The bit you saw was only half of it. Her skin burned, thinking of it. The Hunchback knew. Up here in the tower of Notre Dame he saw how it was. Now and then, with the bells rattling his bones, he saw it like God saw it -- inside, outside, above and under -- just for a moment. The rest of the time he went back to hurting and waiting like Scully out there crying in the wind.