London

54 BC

Fifty-four years before the birth of Christ, at the end of a cold, star-filled spring night, a crowd of two hundred people stood in a semicircle by the bank of the river and waited for the dawn.

Ten days had passed since the ominous news had come.

In front of them, at the water's edge, was a smaller group of five figures. Silent and still, in their long grey roves they might have been taken for so many standing stones. These were the druids, and they were about to perform a ceremony which, it was hoped, would save the island and their world.

Amongst those gathered by the riverbank were three people, each of whom, whatever hopes or fears they may have had concerning the threat ahead, guarded a personal and terrible secret.

One was a boy, the second a woman, the third a very old man.

There were many sacred sites along the lengthy course of the river. But nowhere was the spirit of the great river so clearly present than at this quiet place.

Here, sea and river met. Downstream, in a series of huge loops, the ever widening flow passed through open marshland until, about ten miles away, it finally opened out into the long, eastward funnel of the estuary and out to the cold North Sea. Upstream, the river meandered delightfully between pleasant woods and lush, level meadows. But at this point, between two of the river's great bends, lay a most gracious stretch of water, two and a half miles long, where the river flowed eastwards in a single, majestic sweep.

It was tidal. At high tide, when the incoming sea in the estuary reversed the current, this river road was a thousand yards across; at low tide, only three hundred. In the centre, halfway along the southern bank where the marshes formed little islands, a single gravel spit jutted out into the stream forming a promontory at low water, and becoming an island when the tide was high. It was on the top of this spit that the little crowd was standing. Opposite them, on the northern bank, lay the place, now deserted, that bore the name of Londinos.

Londinos. Even now, in the dawning light, the shape of the ancient place could be seen clearly across the water: two low gravel hills with levelled tops rising side by side about eighty feet above the waterfront. Between the two hills ran a little brook. To the left, on the western flank, a larger stream descended to a broad inlet that interrupted the northern bank.

On the eastern side of the two hills, there had once been a small hillfort whose low earthwork wall, now empty, could serve as a lookout post for vessels approaching from the estuary. The western hill was sometimes used by the druids when they sacrificed oxen.

And the was all there was. An abandoned settlement. A sacred spot. The tribal centres were to the north and south. The tribes over whom the great chief Cassivelaunus was master lived in the huge eastern tracts above the estuary. The tribe of Cantii, in the long peninsula south of the estuary, had already given that region the name of Kent. The river was a border between them, Londinos a sort of no-man's-land.

The very name was obscure. Some said that a man called Londinos had lived there; others suggested that it might refer to the little earthwork on the eastern hill. But nobody knew. Somehow, in the last thousand years, the place had got the name.

The cold breeze was coming up the river from the estuary. There was a faint, sharp smell of mud and riverweed. Above, the bright morning star was beginning to fade as the clear sky turned to a paler blue.

The boy shivered. He had been standing an hour and he was cold. Like most of the folk there, he wore a simple woolen tunic that reached to the knees and was fastened at the waist with a leather belt. Beside him stood his mother holding a baby, and his sister little Branwen, whom he held by the hand. For it was his task at such times to keep her in order.

He was a bright, brave little fellow, dark-haired and blue-eyed, like most of his Celtic people. His name was Segovax and he was nine. A closer inspection, however, would have revealed two unusual features in his appearance. On the front of his head on the forelock, grew a patch of white hair, as though someone had dabbed it with a brush of white dye. Such hereditary marks were to be found amongst several families dwelling in the hamlets along that region of the river. "You needn't worry," his mother had told him. "A lot of women think it's a sign that you're lucky."

The second feature was much stranger. When the boy spread his fingers, it could be seen that between them, as far as the first joint, was a thin layer of skin, like the webbing on a duck's foot. This too was an inherited trait, although it did not show itself in every generation. It was as though, in some distant, primordial time some gene in a fish-like prototype of Man had obstinately refused to change its watery character entirely, and so passed on this vestige of its origins. Indeed, with his large-eyed face and his wiry little body, the boy did somehow make one think of a tadpole or some other little creature of the waters, a quick survivor down the endless eons of time.

His grandfather had also exhibited the condition. "But they cut the extra skin away when he was a baby," Segovax's father had told his wife. She could not bear the thought of the knife, though, and so nothing had been done. It did not trouble the boy.

Segovax glanced around at his family: little Branwen, with her affectionate nature and her fits of temper that no one could control; the baby boy in his mother's arms, just starting to walk and babble his first words; his mother pale and strangely distracted of late. How he loved them. But as he stared past the druids, his face broke into a little smile. By the water's edge was a modest raft with two men standing beside it. And one of them was his father.

They shared so much, father and son. The same little tuft of white hair, the same large eyes. His father's face, scoured by crease lines almost resembling scales, made one think of some solemn, fish-like creature. So dedicated was he that the local people referred to him simply as the Fisher. And though other men, Segovax realized, were physically stronger than this quiet fellow with his curved back and long arms, none was kinder or more quietly determined. "He may not be much to look at," the men in the hamlet would say, "but the Fisher never gives up." His mother, Segovax knew, adored his father. So did he.

Which was why, the day before, he had formed the daring plan that, if he managed to carry it out, would probably cost him his life.