Tunnels 03, Freefall

was bearing directly down on him and it was time to run. And run he did, frequently changing direction like a chased hare as he tried to escape.
    But Drake wasn't about to let him off that lightly. He'd mastered the steering levers and it was no effort to keep after the Limiter, who, growing ever more frantic, tripped and fell. Drake drove straight for him, but just at the last moment the Limiter rolled out of the vehicle's path. His rifle wasn't so fortunate and was squashed flat against the bedrock.
    "Your lucky day, matey!" Drake yelled, speeding away from the Limiter as he heaved on a steering lever to get back on course for the Bunker.
    Two kilometers further on, Drake caught his first glimpse of the Bunker wall, and very soon it was all he could see through the windscreen -- a thick grey ribbon stretching across the plain. He eased off the throttle, drawing up just before the wall. Uncertain what he should do next, he glanced at the Coprolite beside him. The man leant over and pushed home another rod. The whole vehicle shook as the cutting wheel mounted on its front began to slowly rotate.
    The vibrations grew and grew, so much so that Drake's vision became blurred. As the wheel reached its maximum revolutions, the Coprolite pointed at the accelerator. Drake gently depressed it and the vehicle edged forward. The wheel touched the concrete wall, its diamond-tipped teeth beginning to bite into it and spewing out huge torrents of dust. Drake watched in fascination as the wheel sliced through the wall like a hot knife through butter. Once the teeth encountered the iron reinforcement inside the concrete, the incredible power of the wheel was fully revealed -- massive chunks of the wall were simply ripped out.
    It took five minutes to penetrate the outer wall of the Bunker, and then the cutting wheel made short work of the internal partitions, slicing through them as if they were made from paper. When he thought he was far enough in, Drake steered the vehicle into a corridor and powered down. He unstrapped himself and went to the rear hatch. As he opened it, he was able to survey the full extent of the devastation the vehicle had left in its wake. The columns supporting the ceiling had been demolished, and great slabs of concrete had fallen in. At least there was no easy way for the Styx to follow after him. He turned to the Coprolites.
    "I don't know how to thank you," he said.
    One of them by the firebox nodded at him. Drake couldn't suppress a chuckle. For a Coprolite that was talkative. He saluted them and then disembarked.
    It didn't take him long to locate the corridor of test cells which Cal and Elliott had first stumbled across. The bright lights made him blink. In complete contrast to the rest of the Bunker, which had fallen into disrepair after decades of disuse, the room was clean and startlingly white. As he walked though the central area, some twenty by ten meters in size, he could see that along both sides were rows of doors. A quick glance through the glass inspection windows in these revealed there wasn't anyone left alive in the cells. Putrefying corpses lay in pools of their own fluid. Drake shook his head. The Styx had certainly found what they'd been looking for -- if these poor guinea pigs were anything to go by, the Dominion virus was lethal and a very real threat to the Topsoil population.
    The thought occurred to Drake that he could try it extract a viable specimen of the virus from one of the corpses -- armed with this, it would be possible to prepare a vaccine, and the Styx plot would be thwarted. But each of the cell doors were sealed around their edges by thick welds and, short of blowing one of them open, he couldn't see how else he could gain entry. And if he was to attempt this, apart from the fact he himself would be infected, he would be responsible for releasing the virus into the atmosphere. Then there was the risk that the air currents might carry it Topsoil. He shook his head, hastily abandoning the idea, and instead investigated the laboratory equipment on a bench against the far wall of the room. There wasn't anything there that resembled viral samples.
    "No time," Drake said to himself, mindful that the Styx might be along at any moment. He used all the explosives in his satchel, planting charges at the base of each of the cell doors. He wasn't going to take any chances -- the heat of the ensuing firestorm would kill any remaining virus and sterilize the area, quite apart from