The tiny parcel was a key wrapped in a note. 'Vanessa,' it read, 'Be ready. Yours, in saecula saeculorum. H.G.'

Latin was not her forte; she hoped the final words were an endearment, not an instruction. She tried the key in the door of her cell. It worked. Clearly Gomm didn't intend her to use it now, however, but to wait for some signal. Be ready, he'd written. Easier said than done, of course. It was so tempting, with the door open and the passageway out to the sun clear, to forget Gomm and the others and make a break for it. But H.G. had doubtless taken some risk acquiring the key. She owed him her allegiance.

After that, there was no more dozing. Every time she heard a footstep in the cloisters, or a shout in the yard, she was up and ready. But Gomm's call didn't come. The afternoon dragged on into evening. Guillemot appeared with another pizza and a bottle of coca-cola for dinner, and before she knew it night had fallen and another day was gone.

Perhaps they would come by cover of darkness, she thought, but they didn't. The moon rose, its seas smirking, and there was still no sign of H.G. or this promised exodus. She began to suspect the worst: that their plan had been discovered, and they were all being punished for it. If so, would not Mr Klein sooner or later root out her involvement? Though her part had been minimal, what sanctions might the chocolate-man take out against her? Sometime after midnight she decided that waiting here for the axe to fall was not her style at all, and she would be wise to do as Floyd had done, and run for it.

She let herself out of the cell, and locked it behind her, then hurried along the cloisters, cleaving to the shadows as best she could. There was no sign of human presence - but she remembered the watchful Virgin, who'd first spied on her. Nothing was to be trusted here. By stealth and sheer good fortune she eventually found her way out into the yard in which Floyd had faced Mr Klein. There she paused, to work out which way the exit lay from here. But clouds had moved across the face of the moon, and in darkness her fitful sense of direction deserted her completely. Trusting to the luck that had got her thus far unarrested, she chose one of the exits from the yard, and slipped through it, following her nose along a covered walkway which twisted and turned before leading out into yet another courtyard, larger than the first. A light breeze teased the leaves of two entwined laurel-trees in the centre of the yard; night-insects tuned up in the walls. Peaceable as it was, the square offered no promising route that she could see, and she was about to go back the way she'd come when the moon shook off its veils and lit the yard from wall to wall.

It was empty, but for the laurel-trees, and the shadow of the laurel-trees, but that shadow fell across an elaborate design which had been painted onto the pavement of the yard. She stared at it, too curious to retreat, though she could make no sense of the thing at first; the pattern seemed to be just that: a pattern. She stalked it along one edge, trying to fathom out its significance. Then it dawned on her that she was viewing the entire picture upside-down. She moved to the other side of the courtyard and the design came clear. It was a map of the world, reproduced down to the most insignificant isle. All the great cities were marked and the oceans and continents crisscrossed with hundreds of fine lines that marked latitudes, longitudes and much else besides. Though many of the symbols were idiosyncratic, it was clear that the map was rife with political detail. Contested borders; territorial waters; exclusion zones. Many of these had been drawn and re-drawn in chalk, as if in response to daily intelligence. In some regions, where events were particularly fraught, the land-mass was all but obscured by scribblings.

Fascination came between her and her safety. She didn't hear the footsteps at the North Pole until their owner was stepping out of hiding and into the moonlight. She was about to make a run for it, when she recognized Gomm.

'Don't move,' he murmured across the world.

She did as she was instructed. Glancing around him like a besieged rabbit until he was certain the yard was deserted, H.G. crossed to where Vanessa stood.

'What are you doing here?' he demanded of her.

'You didn't come,' she accused him. 'I thought you'd forgotten me.'

Things got difficult. They watch us all the time.' 'I couldn't go on waiting, Harvey. This is no place to take a holiday.'

'You're right, of course,' he said, a picture of dejection. 'It's hopeless. Hopeless. You should make your getaway on your own. Forget about us. They'll never let us out. The truth's too terrible.'

'What truth?'

He shook his head. 'Forget about it. Forget we ever met.'

Vanessa took hold of his spindly arm. 'I will not,' she said. 'I have to know what's happening here.'

Gomm shrugged. 'Perhaps you should know. Perhaps the whole world should know.' He took her hand, and they retreated into the relative safety of the cloisters.

'What's the map for?' was her first question.

This is where we play - ' he replied, staring at the turmoil of scrawlings on the courtyard floor. He sighed. 'Of course it wasn't always games. But systems decay, you know. It's an irrefutable condition common to both matter and ideas. You start off with fine intentions and in two decades ... two decades..." he repeated, as if the fact appalled him afresh,'... we're playing with frogs.'

'You're not making much sense, Harvey," Vanessa said. 'Are you being deliberately obtuse or is this senility?'

He prickled at the accusation, but it did the trick. Gaze still fixed on the map of the world, he delivered the next words crisply as if he'd rehearsed this confession.

There was a day of sanity, back in 1962, in which it occurred to the potentates that they were on the verge of destroying the world. Even to potentates the idea of an earth only fit for cockroaches was not particularly beguiling. If annihilation was to be prevented, they decided, our better instincts had to prevail. The mighty gathered behind locked doors at a symposium in Geneva. There had never been such a meeting of minds. The leaders of Politburos and Parliaments, Congresses, Senates - the Lords of the earth - in one colossal debate. And it was decided that in future world affairs should be overseen by a special committee, made up of great and influential minds like my own - men and women who were not subject to the whims of political favour, who could offer some guiding principles to keep the species from mass suicide. This committee was to be made up of people in many areas of human endeavour - the best of the best - an intellectual and moral elite, whose collective wisdom would bring a new golden age. That was the theory anyway

Vanessa listened, without voicing the hundred questions his short speech had so far brought to mind. Gomm went on.

' - and for a while, it worked. It really worked. There were only thirteen of us - to keep some consensus. A Russian, a few of us Europeans - dear Yoniyoko, of course - a New Zealander, a couple of Americans ... we were a high-powered bunch. Two Nobel prize winners, myself included -'

Now she remembered Gomm, or at least where she'd once seen that face. They had both been much younger. She a schoolgirl, taught his theories by rote.

' - our brief was to encourage mutual understanding between the powers-that-be, help shape compassionate economic structures and develop the cultural identity of emergent nations. All platitudes, of course, but they sounded fine at the time. As it was, almost from the beginning our concerns were territorial.'

Territorial?'

Gomm made an expansive gesture, taking in the map in front of him. 'Helping to divide the world up,' he said. 'Regulating little wars so they didn't become big wars, keeping dictatorships from getting too full of themselves. We became the world's domestics, cleaning up wherever the dirt got too thick. It was a great responsibility, but we shouldered it quite happily. It rather pleased us, at the beginning, to think that we thirteen were shaping the world, and that nobody but the highest eschelons of government knew that we even existed.'