the top of the tower, came to life, stabbing along the western perimeter of the roof, but depressed so that it would not blind the guard in the north-west tower. The light died then came on again, this time playing along the southern perimeter, then again faded. The guard appeared to be in no hurry to put out his light. He lit a cigarette, then lifted what appeared to be a hip flask to his mouth. Roebuck hoped that the light would remain on: as long as it did the guard’s night vision was virtually useless.
The curving spikes of the electrified fence were on a level with the base of the watch-tower. The distance, allowing for the angled increase of height, was about forty-five feet. Roebuck stepped back from the hedge, blessing the person whose sense of privacy had driven him to such horticultural lengths, removed the coil of rope from his shoulders and took about eight loops in his right hand. The free end of the rope had already been made into a running noose. The rope itself, hardly as thick as the average clothes-line, looked as if it might be fit for tying up a parcel but no more than that. It was, in fact, made of steel-cored nylon with a breaking strain of 1400 pounds.
He parted the hedge again and peered down. Kan Dahn and Manuelo were standing, apparently chatting aimlessly, at the corner of the main street and the south lane. The main street was empty of all life, except for passing cars, which were of no concern: not one driver in a thousand ever looks upward at night.
Roebuck stood up on the parapet, swung the rope once round bis head and on the second circle let it go. With what seemed a childishly simple inevitability, the rope snaked outwards and upwards and the loop settled over precisely the two spikes he had chosen. Roebuck did not attempt to draw the noose tight; he could easily have pulled it off the outward curving spikes. He gathered up all the remainder of the rope and threw it across the street to land precisely at the feet of Kan Dahn and Manuelo. They picked up the rope and disappeared along the south lane: the rope tightened and settled down on the base of the spikes.
The first half of the journey along the power cable towards Lubylan Bruno accomplished without too much difficulty. The second part taxed all his powers, his innate ability, his reaction, his superb sense of balance. He had not appreciated that there was such a sag in the cable nor that he would be faced with so steep an upward climb; nor had he bargained for the increasingly frequent gusts of wind. They were slight enough, to be sure, but to a man poised in his precarious position even the sharp increase of five miles an hour in wind speed could have been lethal. As it was it was strong enough to make the cable sway in a highly disconcerting fashion. Had there been the most infinitesimal coating of ice on the wire he could never have made it. But make it he did.
The cable was clamped into a giant insulator held in place by two anchoring wires attached to the wall. Beyond the insulator, the cable looped upwards through another insulator in the base of a heavy switched breaker covered by a plastic hood. To switch off that breaker would nullify the danger that might be caused by someone discovering the PowerStation break-in and switching on the circuit that Bruno had already broken: but that twin- pronged switch, sunk though it almost certainly was in a bath of oil, might make enough noise on release to alert the guard in the south-east watch-tower, no more than ten feet distant. Bruno decided to leave it for the moment. He unscrewed the balancing pole, bound it together and suspended it from an anchoring wire, unlikely though it was that he would be using it again. Getting over the fence of those outward curving spikes would be no problem. It was only about three feet above his head, and all he had to do was to hoist himself up to the top of the breaker and almost literally step over. But here was also the moment of greatest danger — the first time he would be completely exposed to observation. He threw a loop of rope over a spike, hoisted himself up until he was standing on the breaker, his head at least four feet above the top of the spiked fence. The massive flat-topped wall was at least thirty inches thick. A five-year-old who didn’t suffer from vertigo could have toddled around the top perimeter with ease; but the same five-year-old would have been suicidally open to the repeated and irregular probings of the watch-tower searchlights along the perimeter walls. And, just at that moment when he was about to step over the curved spikes of the steel fence, a searchlight bloomed into life. It came from the north-east tower and the beam traversed the length of the east perimeter wall he had been about to mount. Bruno’s reflex action was instantaneous. He crouched below the top level of the wall, holding on to the loop of the rope to keep himself from toppling outwards. It seemed very unlikely that the guard would pick up any object so small as the tiny bight of rope round its anchoring spike and so in the event it proved. The searchlight beam moved away through ninety degrees, briefly traversed the north wall then died. Five seconds later Bruno stood on top of the wall.
Five feet below on the opposite side was the roof of the detention block. The entrance to the watch-tower had to be from there. Bruno lowered himself to the roof and made his crouching way along to the base of the tower.
A flight of eight angled wooden steps led up to the tower platform. As Bruno glanced upwards a match inside the tower flared and he had a glimpse of a figure with a fur hat and turned-up collar of a greatcoat lighting a cigarette. Bruno unscrewed the cover of the gas-pen and soundlessly mounted the stairs, putting his left hand on the door. He waited until the guard drew heavily on his cigarette, opened the door without undue haste, aimed the pen at the red glow and pressed the clip. Five minutes later he arrived, via the detention block roof, at the north- east watch-tower. His stay there occupied him no longer than had his brief sojourn at the first tower. Leaving the second guard there as immobilized and silenced as the first, he made his way back along the east wall, lowered himself down to the breaker and gently pressed down the lever. The muffled thud could not have been heard more than a few feet away, for as he’d guessed the switch had been immersed in a bath of oil. He returned to the south-east tower, peered over the south wall and flashed his torch three times in rapid succession, then pressed it on and left it on. A recognition flash came from the south lane below.
Bruno doused his light, produced a considerable length of weighted cord from a capacious pocket and lowered it. He felt pressure come on the end followed by a gentle tug and immediately started reeling in the cord. In very short order indeed he had in his hands the other end of the rope that Roebuck had succeeded in attaching to the spikes at the south-west corner of Lubylan. He pulled it taut but not too taut — the steel core of the nylon ensured that the sagging factor would be negligible — and fastened it securely. He now had a rope that ran the full length of the outside of the southern wall, three to four feet below the base of the spikes. For an aerialist and high-wire specialist it was as good as a public highway.
It was a fifty yard trip to the south-west tower and he made it in under three minutes. With the rope to walk on and the base of the curved spikes for support it was, for Bruno, a ridiculously easy passage. Once, but then only very briefly, he had to duck low when the searchlight of the watch-tower he was approaching traversed the south wall, but there was never any danger of discovery. And within a minute of his arrival at his destination a third guard had lost all conscious interest in the immediate future.
Bruno pointed his torch down and signalled four times, this to let those waiting below know that he had arrived but to wait. There was still the final guard to be disposed of, the one in the north-west tower. It could well have been that the guards merely traversed their searchlights when and if the whim took them or there could have been some concerted arrangement, however irregular that may have been. In any event, he could not afford to arouse any degree of suspicion. He waited until the remaining guard had made a couple of perfunctory traverses with his searchlight, dropped down to the roof of the research building — like its eastern counterpart it was five feet below the level of the wall — and made his silent way across. Clearly the guard had had no suspicion at all. Bruno made his way back to the south-west watch-tower, flashed his torch twice and lowered his weighted cord again. A minute later he was securing a heavy knotted rope to the base of the spikes. He flashed again, waited a few seconds and gave the rope an experimental tug. It was bar-taut. The first of his companions was on his way up. Bruno peered downwards to try to identify the climber, but the gloom was too deep to make positive identification: from the bulk of the shadowy figure it looked like Kan Dahn.
Bruno embarked on a more careful examination of the roof. There had to be an access hatch for the watch- tower guards, for there was no such vertical access in or near the towers themselves. He located it almost at once by a glow of light emanating from a partially covered hatchway close to the inner edge of the roof, about halfway between the north and south walls. The hatchway cover, vertically sided, curved through an arc of ninety degrees, whether to obscure the light from above, which seemed unlikely, or to give protection against the weather to the hatch below, which seemed more probable. Bruno hitched a cautious eye round the corner of the cover. The light came from a heavily meshed square of plate glass set in a hinged trap-door. Looking down, Bruno could see only a part of the bleak room below but what he could see was enough. There were four guards there, fully clothed, three of them lying, apparently asleep, on hinged canvas bunks, the fourth, his back to Bruno and facing an open door, playing some sort of solitary card game. A vertical steel ladder ran from the floor of the room to the side of the trapdoor. Gingerly, Bruno tried the hatch, but it was locked, probably bolted from below. The place might not, as Harper had said it was, be guarded like Fort Knox, but they certainly took every precaution against the most unlikely occurrences. Bruno moved away and looked down over a low parapet into the courtyard. There were no immediate
