'You don't seem comfortable.'

The man who had been sweeping was resting on his broom, studying Harry. Harry saw that he had a crucifix on a chain around his neck, and that his black robe looked like a habit.

'I'm sorry, brother. I didn't realise – I would have paid my respects-'

The brother brushed that away. He might have been about forty, a tonsure neatly cut into greying hair. He looked sleek and comfortable, but his brown eyes showed a sharp intelligence. 'And I should not have crept up on you – not before a tomb like this, at any rate! But I don't apologise for reading your soul, for it's written on your face.'

Harry felt resentful. 'I'm not here to pray but to meet a man.'

'Geoffrey Cotesford from York?'

'You know him?'

'Only too well.' The friar stuck out his hand. 'I'm Geoffrey. I am glad to meet you, Harry Wooler.'

Harry shook the hand uncertainly.

'I was early.' The friar held up his broom. 'The door was unlocked – careless, that – and I saw the broom resting against a wall, and I thought I should make myself useful. You have a businesslike look about you – I expected that. I'm here on business myself, in fact.'

'I thought you Carthusians were contemplative.'

'Well, we are, some of us. But we have other vocations. I always had too restless a mind to be bothering God with my fragmentary prayers. So I became involved in my house's business affairs. We Carthusians make a bit of a living from the wool trade too, in fact. And I have always been more interested in the souls of others than in my own, a disadvantage for a contemplative! Your soul is as transparently displayed as this poor old fellow's desiccated heart, Harry.'

'It's just so gloomy,' Harry admitted. 'Transi tombs and chantries, monks murmuring your name long after you are dead. The priests say we must all long for the afterlife. Fair enough. But why long for death?'

Geoffrey studied him. 'Ah, but death sometimes longs for us. You're a young man, Harry, and like all old fools I envy you your youth. But as you grow older you'll develop a sense of the past. And our past contains a great calamity, a time when the dead invaded the shore of the living.'

'You mean the Mortality.'

'The Great Mortality, yes. The Big Death. My own grandfather told me tales of what his grandfather, who lived through it, saw for himself. England used to be crowded, you know! But everybody was stirred around by war, and the cities were brimming with filth… Well. We were ripe for the plague. In London, half the population died off in a few years. Think of how it was for the living, Harry, as all those faces around you melted away. The shock left scars in their souls, I think. No wonder they carved these transi tombs, memorials of a world become a vast boneyard.'

Harry was restless, feeling he was being preached at. 'You wrote to me about Agnes. Where is my sister?'

'Far from here, I'm afraid. She's in York. And you must travel to her; she can't come to you. You'll see why. But she's asking for you. Big brother Harry! And, you know, to understand your sister's situation, you will have to think about history – I mean, your family's. Your ancestors weren't always wool traders. You'll see, you'll see…'

'My business – I've work to do.'

'I know,' said Geoffrey. 'But you'll come with me even so, won't you? A spark of duty is bright under that woollen merchant's shirt. I see that in you too.'

These words made Harry feel trapped. With a mumbled apology he hurried down the aisle to the door, and drank in the reassuringly foetid air of the Strand.

Spain crushed James's soul.

The mule train plodded across a landscape like a vast dusty table, where nothing grew but scrub grass and rough untended olive trees, nothing moved but skinny sheep, and there was no sound but the raucous singing of the muleteers echoing from ruined battlements, and the thin mewl of patient buzzards. And, James knew, the journey could only end with more strangeness. For he was travelling to Seville, where, it was said, the Anti-Christ was soon to be born.

His companion and employer, Grace Bigod, was not sympathetic. She was a formidable woman in her forties, perhaps twenty years older than James. Her face was beautiful in a strong, stern, proud way; her greying blonde hair was swept back from her brow. And, sharp, bored, she picked on James. 'What's the matter, Friar James? All a bit much for you?'

'Everything's so strange.'

'Well, of course it's strange. We're a long way from England now.' Her fine nostrils flared as she sucked in the air. 'Smell it! That spicy dryness, the wind straight off the flats of the Maghrib. My family have roots in the Outremer, you know.'

He nodded. It was well known in James's house in Buxton that Grace and her family were descended from a woman called Joan, who had fled Jerusalem when it fell to the Saracens more than two centuries ago.

'Maybe the country of the Outremer is like this – hot, dry, dusty. Maybe there is something in the very air that pulls at my blood. Or maybe it's the stink of the last Muslims in Spain, holed up in Granada. This is the crucible of the whole world, James! The place where the sword-tip of Christianity meets the scimitar-tip of the Moors, a single point of white heat. What do you think?'

James saw only a landscape wrecked by war and emptied by plague. He turned inward, trying not to see. He longed to be safely enclosed within the reassuring routines of his Franciscan monastery.

But Grace and her forebears were generous supporters of the house, and had been for generations. It was through her family's influence that the house was committed to its strange and dark project, a secretive work centuries old. It was through Grace's influence that James, who longed only for a life of scholarship devoted to the peace of Christ, found himself studying terrible weapons of war.

And it was through her influence, her peculiar desire to bring on the end of the world, that he had been dragged from his book-lined cell and been brought all the way across Europe to this desolate, prickly landscape. Her purpose was to sell her Engines of God to the King and Queen of Spain, and she had a copy of the Codex of Aethelmaer, and a summary of two centuries' worth of its development, tucked in her bags.

James did not want to be here. But there was purpose in all things, he told himself. God would show him the true path through the strange experiences to come. He crossed himself and mumbled a prayer.

Grace watched him, hard-eyed, analytical, and she laughed. She was a vigorous, physical woman. Sometimes she stared at him, as if wondering what shape his body was under his habit. And at night, when they stopped in towns or taverns, she would come close to him, brushing past so he could smell her hair, and see the softness of her skin. James knew she felt not the remotest attraction to him, and that this was all part of her bullying of him. But he was unused to women, and his youthful body's reaction to her teasing left him tormented. She made him feel crushed, pale and pasty and worthless, less than a man. And she knew it.

It was a relief when the caravan at last reached Seville, and James was able to get away from her company, if only for a short while. But Seville had its own mysteries.

The Guadalquivir reminded him a little of the Thames in London. Navigable from the sea, the river was crowded with ships, and the wharves and jetties were a hive of activity, where sailors and dockers, beggars, whores and urchins worked and laughed, fought and argued in a dozen languages – the usual folk of the river, James thought, just as you would find in London. Trade shaped the city's communities too; Seville was home to officers and sailors who had participated in Spain's explorations of the Ocean Sea, and there were Genoese and Florentine bankers and merchants everywhere.