The Roman family had been welcomed by their neighbours. They were some distance from the nearest hill fort, the centre of the local branch of the great Dubunni tribe, but the area was safe and free from danger. Their farmstead though not large was comfortable, the main house, round and reed-thatched like those of their neighbours was most of the time warm and dry and well appointed. But it could not keep out the creeping damp of the autumn mists, nor the bone-aching cold of the winter winds. They made friends, they had servants and slaves to work the small patches of ground where they grew beans and peas and in the larger fields barley and oats and to watch over the sheep which grazed on the hills around them. In the summer the countryside was benevolent and beautiful, rich in game and fish and very fertile. The warmth of even this northern sun penetrated Petra’s aching body and gave her some relief, but in the winter the girl grew more and more ill until she was crying with pain. The healers from the settlement helped her. They gave her decoctions made from the local willow trees which brought down her fever and let her rest. They were kind and reassuring. She would grow out of it, they said. This ailment was common amongst young girls in this country. Soon she would improve.

Then they met the beautiful and enigmatic Mora and Petra had made a friend and thirteen-year-old Romanus had fallen in love. Mora had come one day with one of the older, most experienced of druid healers. Mora was, he said, the daughter of Fergus Mor, the college father, the most senior druid on the island and she had a gift such as he had not seen in years. He felt that she would build up a rapport with Petra which would benefit them both. He handed over the case to the young woman, scarcely more than a few years older than Petra herself, and from that day the sick girl improved. Until now. A particularly vicious wind had blown from the north for days now, cutting Lydia to the bone. She could not begin to think how Petra must be hurting for the girl to cry so piteously.

Romanus had not been able to bear to see his sister in such pain. ‘I’ll go and fetch Mora,’ he said at last, and Lydia had let him go. What else could she do? She couldn’t stop him going to find the object of his infatuation now he had an excuse, and Mora was not due to come for at least a month. Besides, it was not far. It would mean running down through the woods and fields, then he would have to take one of the dugout canoes, and thread his way across the low-lying fens, following the deeper channels between the willow and alder and reeds, to the centre on the island where Mora lived. Easy for a boy of thirteen, but even so for reasons she did not quite understand, she had been filled with misgivings. The weather was bad, and Petra had clung to her brother begging him not to go. ‘Wait for Papa to return,’ she wailed. ‘I can hang on. There is enough of the medicine left.’

Lydia had glanced at the small jar on the shelf and shaken her head. There was barely any left at all.

The letter had come only hours after Romanus had set off, a scroll from one of the traders based on the coast, dropped off at the door by a young man on horseback. It was addressed to Gaius.

I thought you should be aware that there is a man here claiming to be your brother, and he is indeed very like you. He has been asking where you are and several of the traders have told him how to find you. I thought it strange that he did not know where his own brother lived, and I did not like his demeanour. Forgive me if I have misjudged the situation, but I send this missive with good intentions.

Lydia’s hands crushed the parchment and she let it fall. She was trembling all over. This could not have happened. For thirteen years they had been free of Flavius. They had thought themselves safe from his malign attentions; thought never to see or hear from him again. How had he tracked them down? Had he gone back to Rome to consult the seer? Why had he come? After all this time surely he did not still harbour the old grudges. She became aware suddenly that Petra was studying her face. ‘Mama, what is it?’

Lydia took a deep breath. ‘A message for your father, child. It seems the messenger missed him at Axiom.’

Why had he missed him? Her heart missed a beat. Gaius had been there for several days now. Had he left for home before Flavius arrived, and if so why had the messenger not overtaken him on the track? Where was he? A gust of wind battered the house, causing the fire to smoke, stirring the floor coverings and making the lamp flames dip and flare and she suppressed a groan of anguish.

There was no sign of Gaius that day or the next, nor of Flavius. And still Romanus had not returned. On the third morning she decided she must go after her son. The daughter of their neighbour had come to see Petra, bringing a gift from her mother of two freshly tanned sheepskins for her bed and the girl agreed to stay until Lydia came back. She stood for a long while outside the house staring down the track towards the north. There was no sign of anyone coming up the long slope from the woods. She must pray to the gods to protect her daughter and go to find Romanus and bring him home.

She took one of the farm ponies, making good speed on the soft muddy ground, heading west down the track towards the levels. It had stopped raining and a fitful sun was peering between the clouds, reflecting in the puddles. Once at the edge of the mere she would have to find someone to take her across to the island. Normally she would have enjoyed such a journey. The wind had backed into the west and was warmer now and more gentle. Her pony was frisky, pleased to be out of its pen. As she gained the more level ground the going was easier and the trackway through the trees firmer beneath the pony’s feet.

She drew up at last at the landing stage and slid from the pony’s back. The place was deserted. There were no boats pulled up on the mud. It was then she heard the swans circling overhead, swans which her Celtic neighbours said carried the souls of dead children to the otherworld.

Ben glanced across at Abi as they walked slowly through the garden towards the church. It was a glorious morning, the sunlight catching the turning leaves and changing them to burnished gold and crimson and tawny. They stopped beside the ruins, staring at the remnants of the walls. ‘They started to excavate in the late thirties, I believe,’ he said after a long silence as they stood looking down at the stones. ‘They found quite a lot of stuff from the Roman villa. Then the war came and they hastily covered most of it up. They never quite got round to it again.’

‘Mat and Cal told you I thought I saw a ghost or two yesterday?’ Abi thought it better to take the bull by the horns.

Ben nodded.

‘Have you ever seen them?’

He shook his head. ‘Cal is the psychic one amongst us. But there have been lots of stories down the centuries.’

‘All my life I’ve seen things, and suspected I was what for a want of a better term is called psychic,’ Abi said thoughtfully,’ but I’ve never really seen ghosts in my life before. Then a few weeks ago in Cambridge I saw a whole lot of them. And other strange things. And then there was no doubt in my mind at all as to what they were. It’s as though something has switched on this ability -’ She stopped in mid-sentence.

Ben waited silently. Listening was something he was good at. A long attentive silence, relaxed, not threatening. He would wait until she was ready to go on. When she did she had changed the subject. Whatever it was she had thought of, she was not ready to talk about it yet. ‘Does Kier know where I am?’

Ben shook his head slowly. ‘Not unless you have told him yourself. Bishop David was very clear on that point. He told me that you had requested that neither your father nor Kieran Scott should be told where you were going.’

‘Kier frightened me. There was something in his eyes. A fanaticism which I have never seen in anyone before.’ She shook her head miserably. ‘He kept saying God had planned for me to move in to look after him, then in the next breath he said such terrible things about me. He accused me of being a witch!’ It was a cry of anguish. ‘And who knows, maybe he is right. That’s why I can’t go on being a priest.’

Ben sighed. It was not for him to question the decision of a bishop, not even David Paxman, but as far as he knew Kieran had been allowed to stay in his parish. Ben could not imagine why if the man was becoming unhinged. ‘Shall we walk on a little way? You will have the chance to do a lot of thinking while you are here, Abi, and if you need to, you will be able to pray, too. You must not let this man give you cause to doubt yourself. I suggest you take things slowly. Make no irrevocable decisions at this stage. We can discuss the future when you have had a chance to recover. You have had a lot to deal with over the past few weeks. There is no hurry.’

Abi smiled at him. ‘You are good at this.’

‘Good at what?’

‘Consolation. Advice. Spiritual ice packs.’

‘I’ve had a lot of practice over the years.’ Ben nodded with a resigned smile. ‘Make full use of me, Abi. Use me as a sounding board, a punch bag, an echo chamber. Whatever you like. I can take it. And in the meantime let me show you the way to my favourite church. I want you to go there every day. Several times a day if it helps. It is a place of solace and peace and safety.’

The little church towards which they were heading stood on an outcrop of land very similar to the one on which Woodley was built. Two small islands in the flat green of the fields, side by side, close together. So close that the ancient orchards which surrounded Woodley’s gardens, spilling down the side of the hill, were separated from the ancient churchyard on the neighbouring slopes, only by a crumbling wall and a lych-gate roofed in ancient silvered oak.

They never reached it. As if by some unspoken mutual agreement they stopped at the gate at the foot of the little overgrown graveyard, spending several minutes in silent contemplation of the yew trees and the wild flowers growing on the graves, listening to the gentle gossip of the jackdaws on the squat, Norman tower before quietly turning to climb back towards the house. When Abi went there to pray she would go alone.

An hour later Abi was in her bedroom kneeling in front of one of her suitcases. In the bottom, wrapped in a sweater, was the lump of crystal. She had run out into the garden moments after her father had hurled it out of the window, her heart in her mouth in case it had shattered on the paving stones beneath. Looking up she had seen that he was still standing at the attic window, staring out. He did not react as she had walked outside into the sunlight, staring round, looking for it. When she failed to spot it at once she feared she might not find it at all amongst all the flowerbeds and plants and shrubs but she did, almost at once. It was lying on a patch of short grass near the little fountain, the sunlight reflecting off one of its clear glassy faces. She couldn’t miss it. It was as though it had called out to her. Pushing the thought aside she had scooped it up, glancing quickly up at the window of her mother’s boudoir. There was no sign now of her father. With a sigh of relief she turned back to the French door and through to where her cases were standing in the hall. In minutes she had loaded all her belongings into the car and driven away.

She unwrapped the crystal carefully and put it down on the window sill where the sunlight immediately caught one of the faces, sending prisms flashing round the room. Its power was almost tangible. It felt as if she had been administered a double shot of caffeine. Jumpy. Alert. All her senses suddenly in overdrive, her heart thudding uncomfortably. Spontaneously she stepped back from it and at once felt a diminution of the sensations. The thought that had come to her earlier as she was talking to Ben was resurfacing. It was since she had touched the crystal that first time in her mother’s room she had begun to see ghosts so clearly. To experience them in a way which brooked no denial. The shock of her mother’s death and the logistics of leaving her job and her flat and parting from her father had distracted her from analysing what had been happening to her. Now, for the first time she concentrated on the stone. It was after she had first held it that she had become aware of people’s auras, that she had felt able to communicate in some strange way with the dead, that she had experienced this absolute certainty. She shivered. Was this what her mother had been so pleased about? The fact that her daughter had felt the crystal tingling beneath her fingers. Was this what Laura had been going to tell her about? And if so, why had she thought it would destroy Abi’s Christian faith? She reached out and ran her finger over the crystal face experimentally. It gave off a crackle and a spark. She jumped back. But of course that was natural. After all, crystals had power, the piezoelectric effect. That was why modern technology was dependent on them. She groped in her memory for the definition in her science books at school. It had been something to do with the fact that quartz under pressure produces electricity naturally. It was inherent in its structure. There was nothing spooky about it. This was a big one. It had enormous power. The Serpent Stone, her great-great-grandmother had called it in her note. She looked down at it thoughtfully, hesitant about touching it again. Slowly she put her finger out towards it. The crackle came while it was still several inches away. It wasn’t like an electric shock. It merely made a sound like a hiss, a presence trying to make itself heard. The hiss of a serpent. Was that where it had got its name? Or of a radio, searching for a station. ‘That’s it, isn’t it,’ she whispered. ‘You are trying to tune in.’ Almost fearfully she laid her finger on the clear face again, touching it lightly and instantly removing her finger. As the contact was made a sound rang out in the room, a split second of speech, too short for her even to catch the words. It was there and in a tenth of a second it was over. She swallowed. Do it again. More slowly this time. This time she laid two fingers side by side on the crystal face and left them there. Nothing. She moved away, astonished to find she was trembling. Taking a deep breath she approached it again and once again touched it, this time just with her index finger. Nothing. ‘OK. So I’ve offended you,’ she murmured. ‘Last chance.’ Picking the crystal up, she turned it round in the sunlight from the window, once more filling the room with dancing lights. And figures. Two figures. For a fraction of a second, standing by the door. Two shadowy shapes, barely recognisable as human. She almost dropped the crystal. Putting it back on the window sill she stared at the place where the figures had been. There was nothing there now. No prisms, no colours flickering against the wall, no figures. Nothing.