Ansell had no idea where they were; he followed MacConnachie blindly.

By now the destructiveness of their passage had turned against them, for the stalks, as they broke, presented dozens of jagged edges that lacerated their arms and shoulders, leaving slivers of shredded cane embedded in the flesh. They bled freely.

After no more than a minute or two, they were so torn and winded they had to stop. MacConnachie sagged against the stalks, unlocking his jaw to let the case fall, and sucked in great gasps of insect-packed air, his entire face, especially round the nostrils, clogged with the press of tiny bodies. Ansell did the same, his brain setting up a sort of high-pitched scream of interference, to prevent the full realization of what he swallowed from getting through.

As soon as the edge of their immediate exhaustion diminished a little, the sounds of the fire came through to them again. They were shocked to hear how close it sounded, as though they hadn’t moved at all, or the fire was travelling faster than they were. Chests still heaving, they looked up and saw the thin stain of smoke sweep past overhead, rushing towards the same destination as themselves. Faster or no, the fire was travelling in the same direction, and must be spreading sideways as well.

MacConnachie snatched up the suitcase, thrust the handle between his teeth, and they crashed forward once more.

A few minutes later, the helicopter found them. The veering disturbance of their progress must have been unmistakable from above.

The first they knew of its arrival was a swirling wind that clamped the nearest stalks about their bodies, and whipped the flecked air into a churning vortex. They glared up and just caught sight of the dull-painted machine as it waddled forward, blades flashing, to disappear from view beyond the straining tips of the stalks.

As the wind passed, the stalks jostled and fretted against one another in the stress of returning equilibrium. MacConnachie looked back a moment, but there was nothing to be said.

Perhaps MacConnachie was growing tired, but it became apparent to Ansell that he was trying to give their floundering progress the appearance of a more measured passage. He had started to time his thrusts, executing them boldly and cleanly, exuding an aura of powerful, professional competence. Imitating him, Ansell found that fear diminished and, against all reason, confidence returned.

The helicopter came back to settle over their heads, blanketing all other sound with the roar of its engine, following sluggishly in their wake. At once the stalks were lashed into activity again, threshing furiously about as they were torn this way and that by the fluctuating down-draught. Progress became teeteringly slow and painful, the maelstrom threatening constantly to suck them off balance, to pitch them forward, or to hold them back and – by suddenly releasing its grip – cause them to be thrown down against the earth. And all the time the stalks lashed them, cracking down across their shoulders, breaking fiercely against their knuckles, beating them in the face, bruising their eyes, and, when they lowered their heads for protection, buffeting their crowns repeatedly. But they staggered on, MacConnachie obviously exerting every ounce of muscle and self-control to maintain his persistent, measured action.