She pointed out to sea, and I followed the sweep of her bare arm. A couple of hundred yards offshore there was a wide red patch in the sea, half a mile wide and perhaps three or four miles long, a deep red dye against the bright blue of the Bay of Biscay.

She turned and looked at me almost scornfully. “You’re from the west coast, you must have seen that once or twice. The ‘red tide’ they call it, over here as well as back home, and it’s quite common in California and Florida. There’s a reason for it that we know all about, and though it’s pretty deadly it’s nothing to worry too much about, unless you’re a fish.”

I took the Leitz Trinovid binoculars from their case under the dash and handed them to Fenrek. “Take a look, tell me what you think,” I said.

He shrugged. “I’ve never seen it myself. Heard all about it, of course. A bad case of it up in the North Sea last spring. Thirty people died from eating contaminated mussels.”

He took the Trinovids and stared out to sea, and then those elegant shoulders shrugged again and he said: “Well named, at least. Just what it is, a red tide.”

“And the question is, who put it there?”

Still using the glasses, he murmured: “Who, and why.” He grunted. “Everybody out looking for it, and there it is, just what they expected to find. Interesting.”

I said: “I can make a pretty good guess at why, but...”

I looked down at Astrid. She was eyeing me over the top of those ridiculous sunglasses as if she thought we were out of our minds. She said, exasperated: “But, for God’s sake, nobody put it there, it just...just comes. To get technical again, the dinoflagellates are single-cell organisms in plankton, and when there’s an admittedly unknown combination of marine and climatic conditions, they multiply at an explosive rate for a while, and then just as inexplicably die. But while they last, you’ve got a red tide, and any fisherman who knows what he’s doing keeps away from it till it’s gone, and doesn’t net fish that turn up dead in the general area. Those poor people down there on the beach ought to have known that, but since they didn’t they’ve taken sick and we’ll have to do something about it. Now, if you wouldn’t mind...”

I said, “It’s cochineal.”

She was already reaching for the ignition switch on that ridiculous little car. Her hand stopped, and she stared up at me in the most complete disbelief: “Cochineal?”

I felt it was my turn to be technical, just to teach this obstreperous young woman a thing or two. I wouldn’t have done that with a stranger, normally, but Fenrek was the strong link between us; it was family. I said: “The females of the Dactylopius coccus; if you want more precision.” She still stared, and I filled in some time for her. “Did you know that the females of the Dactylopius outnumber the males by two hundred to one? But the males are very vigorous, which is just as well, or else we’d never have had any crimsons or scarlets in our history before the invention of the aniline dyes. Have you ever thought about that?”

She said again, incredulous: “Cochineal?”

“They brush the insects off the trees in Southern Spain, dry them in the sun to release the carminic acid...”

“Are you sure?” It was impossible for her to believe.

I said: “Quite true. I have a doctorate in Entomology, among other things.”

She said, impatiently: “No, not that. Are you sure that it’s not dinoflagellates?”

“Not a dinoflagellate in sight. That red tide has been tested and analyzed a dozen times. They can’t believe it at the Research Center either.”

She shook her head, blinking away the astonishment. We heard the dual-note of an ambulance coming along the road from Lisbon, and soon, white-painted, its red light flashing, it slowed down briefly while the cheerful, swarthy driver leaned out and waggled his hand at us, asking a question.

Fenrek pointed to the beach and said: “Ali, na praia, there, on the beach.”

The ambulance, not stopping, lumbered off the road and wound its way slowly down to the beach, and Fenrek said, speaking mostly for the benefit of his niece: “They’ve been inoculated against almost everything in the pharmacopoeia, and they’re still in danger down there. A new disease that no one knows anything about, so what’s the preventative?”

Astrid said promptly: “There’s no such thing as a new disease. What you mean is they haven’t diagnosed it properly yet.”

Fenrek shook his head slowly. He thrust his hands into the pockets of his grey silk suit and wandered off along the edge of the road, his chin sunk on his chest, staring morosely down to the sea. I helped Astrid out of her toy car, and we walked along behind him, watching the ambulance wind its way down there.

In the silence, I felt her looking up at me, and I said, knowing that sooner or later she’d have to know: “When that first case of so-called mussel poisoning was reported last week, they went looking for the red tide, just as a matter of routine. They didn’t find it. Then, during the night, that boat down there was washed ashore with three dead fishermen on board, and this time the tide was close inshore, for everyone to see. It came, perhaps, rather suddenly out of nowhere, but that’s the way it usually happens, and no one remarked on it very much.”

Walking beside me now, she looked tiny and fragile, with that peculiar silver hair piled up high and bouffant and too-carefully groomed; I wondered how she kept it like that in an open car. I said, walking with her slowly: “Again, nothing more than routine, but the Department of Fisheries took samples of the water for analysis. They have to know the strength of the infection so that they can estimate roughly how long it will be before the fishermen can give up starving. And they found that it wasn’t dinoflagellates at all, just plain Dactylopius coccus. Carminic acid derived from cochineal.”

She still didn’t believe it. She said flatly: “It’s impossible.”

“Unlikely, perhaps, but proven possible.”

“But for heaven’s sake, to make a splash in the ocean that size, they’d need...well, they’d need more of the dye than could ever be picked up in the corner drugstore.”

“We guess it would take about fifty gallons of the liquid, and you’re right; in a drugstore you might find as much as four ounces if you were lucky. Or, alternatively, we figure you’d need eight hundred pounds of the dried insects, and at about seventy thousand to the pound, that’s fifty-six million insects. Stimulating thought, isn’t it? The Navy boys are out there now, over the horizon somewhere, pouring five gallons of the liquid into the sea to find out just how big a tide that makes. We’ll know soon just how much was used.”

“But...but by whom, for God’s sake? And why?”

“Quite a problem, isn’t it?”

She looked at me shrewdly. “You said you knew the answer.”

“Not really, not clearly. Perhaps I was boasting a trifle, but...I can think of at least one possible explanation for the why. The who is a fish of a different smell.”

“All right. Then tell me a why, any kind of a why.”

“Let me think about it first. If I’m even half right, there’s something quite terrible going on.”

For a little while, not pushing it, she said nothing. She took hold of my arm when she stumbled on the rough terrain, and didn’t leave go when she’d found her balance again. She looked up at me sideways and said: “Uncle didn’t tell me you were working for him. Or is it with him?”

“Neither. I’m off on a different tack altogether, looking for a man who can clear up a nasty business for...I suppose you could say a client of mine, General Queluz, do you know him?”

She shook her head. I said: “Your uncle does. A nice old man, retired now. Retired rather forcibly, through no fault of his own. I’m trying to help him.”

She swept a long thin arm out towards the ocean. “And this?”

I shrugged. “Fenrek’s baby. We happened to be saying hello to each other when word came through that you were hurrying off down to the beach.” I smiled down at her. “You’re an impetuous young woman, aren’t you?”

She nodded, brooding. “Yes. Yes, I suppose I am.”

We’d caught up with Fenrek now. He stood on the edge of the cliff looking down at the beach. Halfway down, where the track we’d been chasing each other on swung abruptly round an outcrop of rock and then steeply down to the sand, three policemen were standing, watching the ambulance that was below them. They’d been posted there to keep anyone who might pass by away from the little shrimp boat with its cargo of three lifeless men that was now high on the beach above the receding tide.

At five-thirty in the morning they’d been washed up, a dead boat with a dead crew, brought in on the surf and left on the sand. At five-forty, a tired and sad old woman had found them there, a wife and a mother down on the beach in the early hours to help her husband and her two sons land the night’s catch. At five-fifty-five she’d caught the early bus that took the fisherfolk into Cais do Sodre for the fish market, and all she’d said to the other passengers was: O mare vermelho, the red tide, sitting there in black-robed sadness with her tired old weather-beaten face dry-eyed because this was part of her life, as death itself was always a part of the sea which was the only thing she understood; and they too sat there in silence, and at last the bus driver—an educated man from the City—had said to her, reassuring himself: “You tell the police now? Better you tell them.”

She had nodded, and there was silence on the bus again, nobody talking because they knew that for a few days, a few weeks, or a few months, there’d be no fish to sell, nor to eat either. In a little while, one of the men on the bus opened the window and threw out the three fat lobsters he’d been carrying, the lobsters that were to be sold in the market for a week’s good food for his family. Soon, someone else tipped out a basket of mullet; a box of sardines was the next to go. And finally, the bus driver stopped, not a word being spoken, and watched glumly as basket after basket was emptied onto the roadside to rot there in the sun that would soon be up and hot in the bright blue sky.

Very little had been said; then the passengers all climbed back on the bus and went unhappy and empty-handed to the market to spread the bad news around.

“West of the Bocca do Inferno,” they said, “the red tide. Better we cross river and try in Sisimbra, or we all starve.”

Now, down by the water, the two white-coated figures from the ambulance were loading the dead fishermen aboard. The three policemen had found rocks to sit on and were watching idly, smoking their cigarettes and enjoying the sunlight.

Astrid said, brooding: “The woman died, the woman who came in on the bus this morning. The doctor said it was mussel poisoning, and now...now there’s the red tide which caused it, and you say it’s cochineal. It just simply doesn’t make any kind of sense at all.”

“Not till we know more about it, it doesn’t.”

“Could a swarm of the insects find its way into the sea...like...like lemmings, or something? After all, they live in Spain, and that’s not so far.”