Barnes used one dirty fingernail to trace the line of a road from the ferry wharf at Gravesend eastwards along the foot of the chalk hills. Where the Thames had jogged north to swing round the hammerhead, the road angled south to cut across its narrow handle, and then to follow the higher and drier ground a few miles inland of the Thames. "Here’s where they should have got ahead of us," Barnes said. "And here is the bridge—the only bridge—over Yantlet Creek to the Isle of Grain."