Whence could come the dense personnel of such a column as I now beheld? Did those ancient, unplumbed warrens teem with a twisted, uncatalogued, and unsuspected life? Or had some unseen ship indeed landed a legion of unknown outsiders on that hellish reef? Who were they? Why were they here? And if such a column of them was scouring the Ipswich road, would the patrols on the other roads be likewise augmented?