The infuriated owner of the stranded cart was still on the body of the vehicle, brandishing his long whip and howling with anger and frustration. He was not a big man, an inch or so shorter than Ralph, but heavy in the shoulder, and his hands on the stock of the whip were rough as oak bark, baked by the sun and scoured by gravel and the haft of pick and shovel.

"I'll settle your account, you little bugger," he shouted, and again threw back the whip; again Ralph ducked under the flailing lash, but it caught the sleeve of his faded and patched shirt, splitting the rotted material and opening the skin of Ralph's upper arm in a thin red razor cut from which the bright blood bloomed instantly.

Rising from his crouch in the mud, Ralph placed one hand on the wheel mule's withers and used his own impetus and the leverage of his arm to leap high in the air. It was a trick that Jan Cheroot had taught him, the way a good teamsman crosses from one side of the span to another. In mid-air Ralph tucked his legs and swung his body, vaulting cleanly over the mules' backs and landing on the far side of the team alongside the leading wheel. His next jump carried him onto the truck of the cart, and with the same movement he had snatched his own long trek whip from its slot beside the brake handle.

The handle was ten feet long, and the tapered lash another twenty.

A skilled teamsman could cut a fly off the tip of the lead mule's ear with the lash, and Jan Cheroot had trained Ralph: he was good with the whip, very good.

Ralph's lips were a thin chalky white line, his eyes green and furious. The sting of the whip had driven him into murderous, unthinking rage.

"Ralph!" Zouga shouted vainly. He had seen his son like this before. It frightened him. "Ralph! Stop!"

Standing high on the cart bed Ralph shot the lash out to full stretch behind him. It was an easy graceful movement like a salmon fisherman putting up the fly, and in the same action he brought the tip of the whip stock forward, all wrist and shoulders, and the lash whined and reached out to the other driver.

It cut him like a sword stroke, from breast to belt buckle, and only the heavy wet oilskin he wore protected him from serious injury. The torn fabric flapped about his body, and the rain diluted the dribble of blood from the shallow wound.

Ralph's mules swung from the crack of the whip, and the off wheel hooked that of the stranded cart, locking both vehicles hopelessly in the soft mud.

Ralph was too close now to the other driver to stretch the lash, and he reversed the whip stock, using it like a club, and swung it at the man's head.

Below them in the diggings, the Matabele were encouraging their favourite with the fighting "jee!" and it goaded Ralph. He was quicker than the other driver, nimble to avoid his swinging stock, using his own like the fighting sticks with which he had trained so assiduously.

The mules were panicked by the uproar, the crack of whips, the Matabele war chant, the shrieked insults and the bellow of the watchers.

Rosie reared and cut with her fore-hooves, whinnying hysterically, and her team mate lunged and struggled against the jammed off wheel.

Bishop shirked the yoke, turned from it; his hind legs scrabbled on the crumbling edge of the causeway and he went over, hanging in the tangle of reins and chains, kicking and pawing at the air and shrieking wildly.

Then quite gently, like a sleeper awaking from deep slumber, the yellow earthen causeway shook itself.

The movement started below the wheels of the locked carts and the trampling hooves of the terrified mules and then it rippled along the embankment to the neck where it joined the rim of the pit, and at that point a deep vertical crack opened miraculously in the muddy yellow wall. It opened with only a soft wet sound like an infant suckling at the breast, but it silenced the shouting, chanting men who watched.

Suddenly the only sound in the open diggings was the rustle of the falling rain and the shrieks of the dangling mule. On the cart Ralph stood poised like a Greek statue of an athlete, the whip stock thrown back, the cords in his throat relaxing, the insane rage in his green eyes clearing to leave a bemused expression of disbelief; for beneath his feet the earth was moving.

"Ralph!" This time Zouga's voice reached him clearly, and he looked down into the pit, saw their faces, the shock, the terror upon them.

"Run!" shouted Zouga, and the urgency galvanized Ralph. "Get off the roadway."

Ralph threw the whip aside and jumped down off the cart. The sheath knife in his hand again.

The rein that held Bishop, the big grey mule, was stretched tight as an iron bar. It parted cleanly to the touch of the blade and the mule dropped free, twisting in the air so that the men below scattered away, and the heavy body smacked into the mud. Then the beast scrambled to its feet and stood trembling miserably, belly deep in the yellow mud that had saved it.

The earth trembled like jelly under Ralph's feet as he hacked at the traces that held the other three mules and the moment they were free of the trapped cart he drove them ahead of him along the causeway, yelling them into a gallop. The yellow mud shook and tilted as the cracks yawned open, and the entire causeway began to sag.

"Run, you bloody fool," Ralph panted at the man he had been fighting, as he stood in the rain and looked about him, the tattered oilskins dangling about his legs, his expression bewildered.

"Come on, run," and Ralph grabbed his arm and dragged him after the galloping mule team.

one after another the gantries that lined the roadway, some of them with the huge buckets still hanging from the sheaves, began to topple over into the pit, the timber crackling and twisting, the ropes tangling and snapping like strands of cotton.

Ahead of Ralph the three yoked mules reached firm ground and galloped away, whisking their tails and kicking out skittishly at relief from their burden.

The causeway tilted and sagged, so that suddenly Ralph seemed to be running up a steep hill. The driver beside him missed his footing and went down on his knees, and then as he started to slide backwards he threw himself face down and spread his arm as though to hug the earth.

"Get up." Ralph checked his own run, and stood over him.

Behind them the earth growled like a voracious animal, moving gravel grinding upon itself; and there were still fourteen carts out on the collapsing causeway.

Half a dozen of the drivers had abandoned their teams and were running back along the trembling, sagging roadway, but they had left it too late. They stopped in a little group. Some of them fell flat and clung to the earth. One turned and leapt boldly from the edge into the gaping pit.

He plugged into the mud, and three black workers seized him and dragged him to safety, a broken leg twisting and slithering over the mud behind him.

One of the laden carts, with four mules in the traces, toppled over and, as it hit the bottom of the diggings, the weight of gravel shattered it to ragged splinters of raw white wood, and a shaggy black mule impaled on the disselboom screamed with shockingly human agony and kicked wildly. tearing out its own entrails from the gaping wound in its flank.

Ralph stooped and dragged the driver to his feet, pulling him up the steepening incline, but the man was semi-paralysed by terror and hampered by the flapping tails of his heavy oilskins.

The centre of the roadway cracked through abruptly and a hundred feet of it collapsed sideways with a swift rumbling rush, hurling carts and animals into the pit as though from some gigantic catapult.

Ralph glanced once over his shoulder at the terrifying carnage and saw that the whole roadway was going starting from that centre point and running swiftly towards him, a breaking wave of soft yellow earth seeming to be of some thick and viscid fluid, breaking with that grinding whisper.