The Fog Horn blew.

"I made up that story," said McDunn quietly, "to try to explain why this thing keeps coming back to the lighthouse every year. The Fog Horn calls it, I think, and it comes...."

'But " I said.

"Sssst!" said McDunn. "There!" He nodded out to the Deeps.

Something was swimming toward the lighthouse tower.

It was a cold night, as I have said; the high tower was cold, the light coming and going, and the Fog Horn calling and calling through the raveling mist. You couldn't see far and you couldn't see plain, but there was the deep sea moving on its way about the night earth, flat and quiet, the color of gray mud, and here were the two of us alone in the high tower, and there, far out at first, was a ripple, followed by a wave, a rising, a bubble, a bit of froth. And then, from the surface of the cold sea came a head, a large head, dark-colored, with immense eyes, and then a neck. And then--not a body--but more neck and more! The head rose a full forty feet above the water on a slender and beautiful dark neck. Only then did the body, like a little island of black coral and shells and crayfish, drip up from the subterranean. There was a flicker of tail. In all, from head to tip of tail, I estimated the monster at ninety or a hundred feet.

I don't know what I said. I said something.

"Steady, boy, steady," whispered McDunn.

"It's impossible!" I said.

"No, Johnny, we're impossible. It's like it always was ten million years ago. It hasn't changed. It's us and the land that've changed, become impossible, Us!"

It swam slowly and with a great dark majesty out in the icy waters, far away. The fog came and went about it, momentarily erasing its shape. One of the monster eyes caught and held and flashed back our immense light, red, white, red, white, like a disk held high and sending a message in primeval code. It was as silent as the fog through which it swam.

"It's a dinosaur of some sort!" I crouched down, holding to the stair rail.

"Yes, one of the tribe."

"But they died out!"

"No, only hid away in the Deeps. Deep, deep down in the deepest Deeps. Isn't that a word now, Johnny, a real word, it says so much: the Deeps. There's all the coldness and darkness and deepness in a word like that.""What'll we do?"

"Do? We got our job, we can't leave. Besides, we're safer here than in any boat trying to get to land. That thing's as big as a destroyer and almost as swift."

"But here, why does it come here?"

The next moment I had my answer.

The Fog Horn blew.

And the monster answered.

A cry came across a million years of water and mist. A cry so anguished and alone that it shuddered in my head and my body. The monster cried out at the tower. The Fog Horn blew. The monster roared again. The Fog Horn blew. The monster opened its great toothed mouth and the sound that came from it was the sound of the Fog Horn itself. Lonely and vast and far away. The sound of isolation, a viewless sea, a cold night, apartness. That was the sound.

"Now," whispered McDunn, "do you know why it comes here?"

I nodded.

"All year long, Johnny, that poor monster there lying far out, a thousand miles at sea, and twenty miles deep maybe, biding its time, perhaps it's a million years old, this one creature. Think of it, waiting a million years; could you wait that long? Maybe it's the last of its kind. I sort of think that's true. Any way, here come men on land and build this lighthouse, five years ago. And set up their Fog Horn and sound it and sound it out toward the place where you bury yourself in sleep and sea memories of a world where there were thousands like your self, but now you're alone, all alone in a world not made for you, a world where you have to hide.

"But the sound of the Fog Horn comes and goes, comes and goes, and you stir from the muddy bottom of the Deeps, and your eyes open like the lenses of two-foot cameras and you move, slow, slow, for you have the ocean sea on your shoulders, heavy. But that Fog Horn comes through a thousand miles of water, faint and familiar, and the furnace in your belly stokes up, and you begin to rise, slow, slow. You feed yourself on great slakes of cod and minnow, on rivers of jellyfish, and you rise slow through the autumn months, through September when the fogs started, through October with more fog and the horn still calling you on, and then, late in November, after pressurizing yourself day by day, a few feet higher every hour, you are near the surface and still alive. You've got to go slow; if you surfaced all at once you'd explode. So it takes you all of three months to surface, and then a number of days to swim through the cold waters to the lighthouse. And there you are, out there, in the night, Johnny, the biggest damn monster in creation. And here's the lighthouse calling to you, with a long neck like your neck sticking way up out of the water, and a body like your body, and, most important of all, a voice like your voice. Do you understand now, Johnny, do you understand?"

The Fog Horn blew.

The monster answered.

I saw it all, I knew it all--the million years of waiting alone, for someone to come back who never came back. The million years of isolation at the bottom of the sea, the insanity of time there, while the skies cleared of reptile-birds, the swamps dried on the continental lands, the sloths and saber-tooths had their day and sank in tar pits, and men ran like white ants upon the hills.

The Fog Horn blew.

"Last year," said McDunn, "that creature swam round and round, round and round, all night. Not coming too near, puzzled, I'd say. Afraid, maybe. And a bit angry after coming all this way. But the next day, unexpectedly, the fog lifted, the sun came out fresh, the sky was as blue as a painting. And the monster swam off away from the heat and the silence and didn't come back. I suppose it's been brooding on it for a year now, thinking it over from every which way."

The monster was only a hundred yards off now, it and the Fog Horn crying at each other. As the lights hit them, the monster's eyes were fire and ice, fire and ice.

"That's life for you," said McDunn. "Someone always waiting for someone who never comes home. Always someone loving some thing more than that thing loves them. And after a while you want to destroy whatever that thing is, so it can't hurt you no more." The monster was rushing at the lighthouse.

The Fog Horn blew.

"Let's see what happens," said McDunn.

He switched the Fog Horn off.

The ensuing minute of silence was so intense that we could hear our hearts pounding in the glassed area of the tower, could hear the slow greased turn of the light.

The monster stopped and froze. Its great lantern eyes blinked. Its mouth gaped. It gave a sort of rumble, like a volcano. It twitched its head this way and that, as if to seek the sounds now dwindled off into the fog. It peered at the lighthouse. It rumbled again. Then its eyes caught fire. It reared up, threshed the water, and rushed at the tower, its eyes filled with angry torment.

"McDunn!" I cried. ''Switch on the horn!"

McDunn fumbled with the switch. But even as he flicked it on, the monster was rearing up. I had a glimpse of its gigantic paws, fishskin glittering in webs between the finger-like projections, clawing at the tower. The huge eye on the right side of its anguished head glittered before me like a caldron into which I might drop, screaming. The tower shook. The Fog Horn cried; the monster cried. It seized the tower and gnashed at the glass, which shattered in upon us.

McDunn seized my arm. "Downstairs!"

The tower rocked, trembled, and started to give. The Fog Horn and the monster roared. We stumbled and half fell down the stairs. "Quick!"

We reached the bottom as the tower buckled down toward us. We ducked under the stairs into the small stone cell. There were a thousand concussions as the rocks rained down. The Fog Horn stopped abruptly. The monster crashed upon the lower. The tower fell. We knelt together, McDunn and I, holding tight, while our world exploded.