Minerva 's got a spacious stairwell running all the way down through the middle of her, just ahead of the mighty creaking trunk of the mainmast, with two flights of stairs spiraling opposite directions so the men descending don't interfere with those ascending – or so doddering Doctors with sacks of pottery-shards do not hinder boys running up from the hold with – what? The light's dim. They appear to be canvas sacks – heavy bulging polyhedra with rusty nails protruding from the vertices. Daniel's glad they're going up the other stairs, because he wouldn't want one of those things to bump into him. It'd be certain death from lockjaw.