The Hope limned a hammerhead-shaped protrusion of Kent with no particular boundary between marsh and water, but instead a mile-wide zone between high and low tide—the river halved its width at ebb. Because Daniel knew where they were going, he traced the flat top of the hammerhead eastwards until he reached the semicircular peen at its seaward end. This was labeled the Isle of Grain. The Thames flowed along its northern cheek, the Medway along its southern. The two rivers met just off the Isle’s eastern tip. And like a couple of porters who drop their loads in the middle of the street to engage in a fist-fight over which had right-of-way, these two rivers, at the place where they came together, let go of all the muck they’d been carrying out to the sea. In this way was built up a vast bank, a bulge growing eastwards from the Isle of Grain’s indefinite shore, and as that bulge reached out into the sea, mile after mile, it narrowed, converged, refined itself into a slim prod sticking far out into brackish water between Foulness Sand on the north and the Cant on the south. At the extremity of that bar was the Buoy of the Nore. The estuary yawned east like a viper’s mouth, the Nore spit thrust out in its middle like a barbed tongue. It was in that cursed in-between depth, too shallow for most vessels and too deep for any beast.