For when a mole burrows a tunnel, he takes heed of the acoustics it creates—not for his entertainment, but so that he may gauge from the sounds it carries to him at any one point potential danger or possible food. A tunnel has to be good to carry the vibrations of a worm more than fifty moleyards; it has to be superbly designed to carry the slinking of a rival much more than one hundred moleyards. This being so, the air currents in a system are very important—for while earth vibrations may carry fifty moleyards and sound in a still system perhaps two hundred, air currents help carry sound a great deal further, and scent as well. But air currents do not happen—they are designed, and it was this aspect of the tunnel into which he entered that impressed Bracken. For the air currents were subtle and complex, the moles having acquired the difficult art (in many systems long forgotten) of creating tunnels in which air flows in different directions at different levels—as water may do in a river, or wind often does in a steep valley.
The advantage of such air currents to a mole who knows them is that they allow him to ‘read’ his tunnels in two directions at once, and sometimes, if he is at an intersection or crosstunnel, even more.
At first Bracken could not easily interpret the sounds he heard or the scents either. That would take time. Though from the scents he could tell that there were no moles about, nor did he expect any. There were, however, other animal smells—voles, certainly, but they’d grab any temporary burrow they could get, and if that included the entrance to a deserted mole tunnel, well and good; the more sinister, sharp smell of weasel came to him, too, though from a long, long way off; but nothing else that was specific, except for the clean, dry smell of fresh vegetation whose roots and scent he realised must enter the Ancient System in many places.
This play on his ears and snout was intoxicating enough, but the impression of the great tunnel he was in was only completed by its awesome size and evident age. Its wall and roof towered above him, giving the immediate impression that it had been burrowed in some long-distant age, when giant moles roamed the earth. The walls were hard and a little chalky, the floors smooth and well packed, while the curves of its roof and corners, and where subsidiary tunnels joined it, were subtle and sinewy.
Set into the walls at irregular intervals were the grey-white roundels of enormous flints, plump with curves and hollows, which added not only to the curious flowing appearance of the tunnels but created a feeling of great antiquity as well.
It occurred to Bracken how extraordinary it was that moles had been able to move these great stones so that they might fit the tunnel—so deliberate did their setting seem—but then he saw that, by some miracle of orientation, the tunnel had been burrowed to fit the existing position of the stones. It was as if, in some way, the ancient moles had taken their cue not from any desire to impose a pattern on virgin soil but from the pattern set by whatever power it was that had first placed the stones. The feeling of age and venerability the tunnel gave him was such that he almost tiptoed along so he wouldn’t disturb the ancient peace.
What he did disturb, however, was the deposit of fine white chalk dust that had settled through time on the floor and rougher parts of the walls. The first big drift he came to he mistook for a rise in the floor, and went unthinking into it so that particles rose about him in a great choking cloud of dust, and he backed away from it, sneezing and gasping, his fur all white.
After that, he watched carefully for the thicker drifts, gradually getting used to the fact that the chalk tended to be deposited on alternate sides of the great tunnel, creating a winding path of clearer floor down the centre of the tunnel—which added to the impression the tunnel gave to a mole travelling down it of dancing or weaving along past the immovable stones of time.
Bracken did not enter any of the subsidiary tunnels that ran off this bigger tunnel on his first two days of exploration. He was too tired and too cautious. His explorations of the Westside, Barrow Vale and the slopes in May and June had taught him that exploration is best done carefully until a mole has a grasp of the orientation of the tunnels accessible from it.
He quickly established that what he had come to regard as the peripheral communal tunnel of the Ancient System ran, at this point anyway, parallel with the cliff’s edge and roughly one hundred moleyards in from it. It ran on up towards the top of the hill where he and Hulver had lain hidden before Midsummer Night, and back down towards the easternmost side of the slopes. There was only one other tunnel running back to the cliff’s edge as did the first one he had found himself in—and this, too, fell sheer to the void below.
