Catherine waited, and then shrugged and turned away. Fastening her robe, she bent down and filled the bucket.

Ransom went over and took her arm. He pointed to the slip road leading down from the embankment. Directly below the bridge the trailer had parked, and the families of four or five adults and half a dozen children were setting up a small camp. Two of the men carried a chemical closet out of the trailer. Followed by the children, they walked down the bank, sinking up to their knees in the white dust. When they reached the water they emptied the closet and carefully washed it out.

"For God's sake…!" Catherine Austen searched the sky. "Doctor, people are filthy."

Ransom took the half-filled bucket from her and lowered it into the water. Catherine watched it glide away on the oily current, her face pale and expressionless. Professor Austen's wife, a noted zoologist in her own right, had died in Africa while Catherine was a child, and Ransom suspected the daughter's eccentricities were less a sign of innate character than of loneliness and vulnerability. Watching her, Ransom reflected that however isolated a man might be, women at least remained his companions, but an isolated woman was isolated absolutely.

Gathering her robe around her, Catherine began to make her way up the bank.

"Wait," Ransom called. "I'll lend you some water." With forced humor, he added: "You can repay me when the pressure comes on again."

He guided her on board the houseboat and went off into the galley. The tank in the roof contained little more than twenty-five gallons, laboriously filled from jerricans he had taken down to the river in his car. The public water supplies, a pathetic trickle all summer, had finally been discontinued three weeks earlier, and since then he had been unable to make good the constant drain on the tank.

He half-filled a can of water and carried it into the cabin. Catherine Austen was strolling up and down, inspecting his books and curios.

"You're well prepared, doctor," she commented. "I see you have your own little world here. Everything outside must seem very remote." She took the can and turned to leave. "I'll give it back to you. I'm sure you'll need it."

Ransom caught her elbow. "Forget the water. Please. I'd hate you to think I'm smug, of all things. If I am well prepared it's just that…" He searched for a phrase. "… I've always thought of the whole of life as a kind of disaster area."

She watched him with a critical eye. "Perhaps, but I think you've missed my point, doctor."

She walked slowly up the bank, and without looking back disappeared toward her villa.

Below the bridge, in the shadow of the pylons, the trailer families sat around a huge garbage fire, their faces blazing like voodoo cultists in the serpentlike flames. Down on the water the solitary figure of Quilter watched them from his coracle, leaning on his pole among the dead fish like a waterborne shepherd's boy resting among his sleeping flock. As Ransom returned to the houseboat Quilter bent down and scooped a handful of the brackish water to his mouth, drank quickly, and then punted himself away below the bridge with his awkward grace.

Ransom prepared a light meal for himself, then spent the next half an hour sealing the hatchways and windows.

As he knelt down by the starboard window in the cabin something flashed past outside, and a sharp voice broke through the silence.

"Doctor! Quickly!"

A long wooden skiff, propelled by a tall sunburnt youth, naked except for a pair of faded cotton shorts, swung up and bumped against the houseboat, materializing like a specter out of the canopy of reflected light that lay over the black mirror of the water.

Ransom went up on deck and found the youth, Philip Jordan, fastening the skiff fore and aft to the rail.

"Philip, what on earth-?" Ransom peered down into the narrow craft. What appeared to be a large nest of wet mattress floc, covered with oil and cotton waste, lay in a parcel of damp newspaper.

Suddenly a snakelike head lifted from the nest and wavered uncertainly at Ransom.

Startled, Ransom shouted: "Philip, tip it back into the water! What is it-an eel?"

"A swan, doctor!" Philip Jordan crouched down in the stern of the skiff, smoothing the clotted head and neck feathers. "It's suffocating in all this oil." He looked up at Ransom, a hint of embarrassment in his wild eyes. "I caught it out on the dunes and took it down to the river. I thought it would swim. Can you save it, doctor?"

"I'll try." Ransom stepped over the rail into the skiff, knelt down by the bird, and searched its mouth and eyes. Too exhausted to move its head again, the huge bird stared up at him with its glazed orbs. The oil had matted the feathers into a heavy carapace, and choked its mouth and respiratory passages.

Ransom stood up, shaking his head doubtfully. "Philip, spread its wings out. I'll get some solvent from the cabin, and we'll see if we can clean it up."

"Right, doctor!"

Philip Jordan, foster child of the river and its last presiding Ariel, lifted the bird in his arms and unfurled its huge limp wings, letting their tips fall into the water. Ransom had known him for several years, and had watched him grow from a child of twelve or thirteen into a tall, longboned youth with the quick eyes and nervous grace of an aboriginal.

Five years earlier, when Ransom had hired a cabin cruiser and spent his first solitary weekends out on the lake, rebuilding his own world from scratch from the materials of water, wind, and sunlight, Philip Jordan had been the only person he could incorporate into this new continuum. One night, as he sat in the well of his craft moored to a deserted quay among the marshes, reading under a lantern, he heard a splash of water and saw a slim brown-faced boy paddle a homemade dinghy out of the warm darkness. Circumspectly leaving a few feet of open water between them, the boy made no reply to Ransom's questions, but watched the doctor with his wide eyes, paddle lightly touching the water. He wore a faded khaki shirt and trousers, the sunbleached remnants of what seemed to be an old scout uniform. To Ransom he was part waif and part water-elf.

Finally, after several long pauses in which Ransom resumed his reading and the boy moved twenty yards away, his blade slipping in the liquid silver of the nightwater, he had come in again and produced from between his feet a small brown owl. Raising it in his childlike hands, he had shown it to Ransom-or more probably, the doctor guessed, had shown Ransom to the owl, the tutelary deity of his water-world-and then vanished among the reeds on the dark surface of the lake.

He appeared again after a lapse of one or two nights, and this time accepted the remains of a cold chicken from Ransom. At last he replied to some of Ransom's questions, speaking in a small gruff voice. He would only answer questions about the owl, the river, and his boat. Ransom assumed he belonged to one of the families living in a colony of beached houseboats further along the lake.

He saw the boy on and off over the next year. He would share a meal with Ransom in the well of the houseboat, and even help him to sail the craft back to the entrance to the river. Here he always left Ransom, reluctant to leave the open water of the lake. Friend of the waterbirds, he seemed able to tame swans and wild geese, and knew every cove and nest in the banks. He was still shy of telling Ransom where he lived, and invariably referred to himself by his surname, the first clue that he had escaped from some institution and was living in the wild. His strange changes of costume-he would suddenly appear in a man's overcoat or an odd pair of old shoes three sizes too big-confirmed this. During the winters he was often close to starvation, going off alone like an animal to eat the food Ransom gave him.

At these times Ransom wondered whether to report him to the vagrancy authorities, frightened that after a cold weekend he might find the boy's dead body following the fish downstream. But something dissuaded him, partly his own increasing influence over the boy-he lent him paper and crayons, and helped him to read-and partly his fascination at the spectacle of this juvenile Robinson Crusoe of the waterways creating his own world out of the scraps and refuse of the twentieth century.

Fortunately, as he grew older the hazards of Philip Jordan's existence diminished, and from this starveling Crusoe scavenging for every nail and fishhook he turned into a wily young Ulysses of the waterfront. His face lengthened and narrowed, the sharp nose and arrowlike cheekbones giving him an alert, resourceful appearance. He carried out various jobs for Captain Tulloch and the yachtsmen in the basin, which made him less dependent on hunting and fish-trapping. Yet many enigmas still surrounded him. Whether these would finally be revealed with the imminent death of the river remained to be seen.

Ransom collected a bottle of turpentine and some cotton waste from a locker in the galley. Perhaps his selfishness in not reporting the youth years earlier might make Philip now pay a terrible price. Although he had managed to eke out an existence for several years, the river was no more a natural environment than a handful of pebbles and waterweed in an aquarium. Its extinction would leave Philip Jordan with a repertory of skills as useful as those of a stranded fish. To date his only enemy had been a fairly pliable nature. Man, on the other hand, had left him alone. Although Philip was not a thief-yet from where had come those mysterious "gifts"-clasp knives, a cigarette lighter, even an old goldplated watch-he had learned the arts of petty pilfering, and one day soon, if no- rain fell, he would be shot down for it like a dog.

"Come on, doctor!" Philip Jordan beckoned him through the hatchway and helped him over the rail. The swan lay inertly with wings outstretched, its plumage glistening with oil in the sunlight.

"Easy, Philip." Ransom knelt down and began to clean the swan's bill. The bird roused faintly, more in response to the manual pressure than in recovery. To Ransom it seemed nearly dead, smothered in the great weight of oil.

Impatiently, Philip Jordan shouted: "Doctor, that's no good! I'll take it down to the galley and soak off the oil." He lifted the great bird in his arms, the wings like a black drooping cross.

Ransom shook his head. "No, Philip, I'm sorry. It's too big a job."

"What?" Philip cocked an ear at him, struggling with the swan's flopping head. "What's the matter?"