"Bond walked to the side of the trapdoor and pushed the upright concrete slab. It revolved easily on is central pivot. Just before its edges shut out the blackness below, Bond heard one terrible snuffling grunt as if a great pig was getting its mouth full. He knew it for the grunt that a shark makes as its hideous flat nose comes up out of the water and its sickle-shaped mouth closes on a floating carcass. " - from the book
