blows off in the wind. No windows; nothing to get an arrow through; and it is built â if it can be said that something is being built when there is no evidence of builders â at such a point on the Wall that no-one can see whether there is a door at the front through which the invisible builders might come, though of course there has to be. And no-one coming or going. At one point the sergeant sits bolt upright in his bed in the middle of the night and shouts out an idea, a realisation: the tower/house/lean-to is being built from the inside. Someone far below them has tunnelled along through the foundations of the Wall itself. The door is on the inside, not the outside. They are being under-mined. For a while the Wall feels different. It is one thing to watch and wait while something encroaches from a place they can keep watch over, even if they never see anything, but an encroachment from below, within, under the very thing theyâre standing on, is something different again.
They renew their efforts, work on a number of plans. Lowering someone down, while the most logical thing to do, has never really been an option, since rope of any appropriate length or thickness is forbidden for fear of escape attempts. Soldiers can be allowed off the Wall one by one as their entitled half-day leave comes due, but a rope might allow all of them off at once, precipitate a group desertion. Now that the house/tower/lean-to is almost two-thirds of the way up the Wall, however, sheets and pieces of clothing might be tied together, a man might be lowered. They draw lots, send down the victor. No outside door as far as he can tell, but it is hard to see. Certainly no path anywhere, no building rubble. And the roof-planks themselves â better to call them beams â are too thick, canât be budged, even with something to prise at them. Perhaps, if he could hammer thick nails into the lower part of the lean-to roof, give himself something to stand on, make a platform, then he could hack, saw, chip his way in, but where to get the nails, the planks for a platform? Requisition them? Explain? They have left it too long, in all their indecisiveness. Now, surely, all they would get would be court martial for incompetence. Better to try to handle it themselves, since thatâs the way they have started. Instead of hacking their way in they could go back to burning. This time the soldier â another soldier, since they are taking turns â could set a fire, but how to do so on the steep slope of the roof?
There is a replacement. The departee is sworn to say nothing. The newcomer â always good to have a fresh mind â comes up with another idea. Wax burns, fiercely, if the heat that starts it is strong enough, and they have a good supply of candles. And it is nearly summer, and the long dry period. Let the sun dry out the wood until it is at its most burnable and then lower a man again, fix balls of wax to the sides â not the roof; fire is wasted on the roof â and light them with burning arrows or a hand-held brand. That way the flames will move upwards along the wood, have a better chance of purchase. But the man sent down, after the months of waiting, sets only himself alight, is barely brought up before the sheets burn through, spends a week moaning in the guardhouse, keeping everyone awake, before they can get him taken away.
The top of the tower/lean-to/house roof is now near the edge of the battlement. They can lean their arms in their usual place and study the grain of the wood. They can roll pebbles down its roof. They can scramble out on it with only the one sheet to hold them, and hammer on its sides. At last, surely, they should be able to see how it has been built, how it has climbed, at last they should be able to hear the builders. But nothing. Even when, not on watch, they stay up all night just to listen. The usual problems with the first morning light. The usual doubts about sleep,