The fog came in at four in the morning, and with it, the silence.

Tamsin had been dreading it all week. Hushwater was not the most dangerous of the Drift Isles. It had killed fewer people than the Orchard, and nowhere near as many as the notorious Sinking Reef. But it had a particular malice all its own, and her father had always said that more sailors went mad on Hushwater than anywhere else in the world.

"It takes your voice," Cormac had told her once, when she was twelve and sitting on a lobster crate with her chin on her knees. "That's the first thing. Not the sight, or the hearing. It takes the sound that you make, and it keeps it. You open your mouth to call, and nothing comes. You can scream until your lungs bleed and the whole world goes on without a whisper."

"Why?"

"Because it's lonely, love. Because it wants to be spoken to, and has nobody."

"Then why don't we just talk to it?"

"Aye," her father had said, with a slow, sad smile. "That's the trouble. It only listens when you've nothing left to say."

She had not understood him then. She did not entirely understand him now. But as the Marrow Lark nosed her way through the pale wall of vapor in the gray hour before dawn, with her engine muffled to a dull throb and her running lights swallowed whole, Tamsin found herself thinking about it more than she wanted to.

She stood at the rail with her hands in her pockets, and kept her mouth shut, and watched the fog unroll before the bow like a bolt of damp gray silk.

Beside her, Juno raised a hand to his lips. "Quiet," he mouthed, with enormous solemnity.

She rolled her eyes.

Behind them in the wheelhouse, Ila stood at the helm, and did not look up.

* * * They found the yacht an hour later, drifting at the edge of the bank.

She was a small cutter, white-hulled, a little battered, with a name painted on her transom in blue script, Quiet Maud. Her sails were furled and her mast was bare. She sat on the sluggish water, dark and still, with two figures crouched in the cockpit. A man and a woman, both in their seventies, both wrapped in oilskins, both with faces as white and anxious as candles.

Tamsin raised the loud-hailer and shouted a greeting.

Nothing came out.

She had known it would. She had braced for it. But the sensation was still extraordinary, a sudden terrible hollowness, as though she had stepped off a stair that was not there. Her lungs worked. Her throat moved. Her mouth shaped the words, clean and clear. And the fog drank them like sand drinking water, without a ripple, without a sound.

She lowered the loud-hailer, and looked at Ila.

Ila had stepped out of the wheelhouse. She stood at Tamsin's elbow, her dark hair already beaded with moisture, her mouth slightly open. She tried it too. A short, startled movement of her lips. A frown. Then she shook her head and drew her hands apart in a wide helpless shrug.

It was oddly funny. Tamsin felt it, a small bubble of laughter rising in her chest, pure and unbidden, and she put the back of her hand to her mouth to stop it.

Ila's eyes crinkled.

For one warm, absurd, perfectly silent moment, they stood on the foggy deck of a salvage tug, two grown women with a combined fifty-nine years of experience in sea rescue, shaking with laughter that made no sound at all.

Then Tamsin remembered who she was, and straightened, and made the hand signal for stand by to receive tow.

* * * It would have been simple, if the fog had stayed where it was.

The plan was a good one. She would take the dinghy across with Ila, and the two of them would rig a tow line to the Quiet Maud's bow, and the Lark would haul her out of the bank on a slow pull. Odo and Juno would stand by with the boathook. It would take twenty minutes, and the whole operation could be conducted entirely in hand signals, which Tamsin had, in fact, drilled with her crew for exactly this contingency.

It was Ila who noticed the change.

They were halfway across the gap in the little inflatable, with Ila at the oars and Tamsin in the bow with the coil of line, when Ila stopped rowing. She sat bolt upright. She turned her head, slowly, left and right, with the intent stillness of an animal that has caught a scent.

Tamsin looked at her.

Ila pointed.

At first she could not see anything. The fog lay thick and gray on every side, a smooth featureless wall. But as she watched, a faint paleness moved in it, a thinning, a slow rolling unwinding, like a curtain being drawn aside by a very careful hand. And behind it, rising out of the vapor on all sides, she saw the shapes of low black rocks.

They were closing in.

It was happening quickly. She could see it in the way the shadows slid, in the sudden crowding of the horizon. The fog bank was contracting, drawing in on itself like a fist, and where it drew, the island rose. Black shingle. A tumbled ruin of boathouses. A long crooked pier, half collapsed, thrusting out into the water like a broken finger.

Tamsin looked at her wrist, where her old brass watch ticked on its strap.

It was five forty. The Open Tide window should have lasted another hour and a half. But the surge numbers had been wrong, as they were wrong on every important morning, and the sea had decided to draw the curtains early.

She grabbed Ila's shoulder.

They stared at each other. And then, with perfect understanding, as if they had been rehearsing for years, they both turned toward the cutter and bent to the oars.

* * * They got the tow line fixed with ninety seconds to spare.

It was the hardest piece of work Tamsin had done all year. The dinghy bucked and swung in the narrowing channel, and the sea heaved beneath her like a living thing, and every few minutes the gray wall of fog slid a little closer. She worked with her sleeves shoved to the elbow and her hair plastered to her face, and she did not once look back, because Ila was behind her, and Ila had never needed to be looked at in a crisis.

They moved as one.

That was the thing she had forgotten. That was the truth that rose up out of seven years of silence and hit her like a wave. She and Ila had always worked this way, a single organism with four hands and two heads, each anticipating the other's move. A hand reaching for a line that had not yet been called for. A shoulder bracing against a swell the other had not yet felt. It was as natural as breathing, and it was as though no time had passed.

The old couple helped as best they could, feeding out slack, hauling in line, with their faces wet and their lips moving in what must have been a continuous murmur of thanks. The man pressed Tamsin's hand in both of his. The woman, a tiny, fierce creature in a yellow sou'wester, kissed Ila on both cheeks, and Ila went pink to the ears.

Then the tug sounded her horn.

It made no noise. Tamsin saw it happen instead, saw the plume of steam spurt from the stack, saw Juno on the foredeck frantically waving both arms. The line went taut. The Lark began to haul. The cutter groaned, and shuddered, and slid free of the bank.

And the fog closed.

It came all at once. One moment she was sitting in the dinghy with the cutter's stern a dozen yards away and the Lark's gray bulk looming in the distance, and the next, the whole world went white. A thick, soft, smothering whiteness, like wool pressed against her face. She could not see her own hands. She could not see the oars.

She felt a hand close around her wrist.

* * * They did not remember afterward how they reached the shore.

It was the strangest kind of blindness. Not darkness, but pallor, a vast soft uniform blankness, and in it nothing existed except the two of them. Tamsin could feel the rubber of the dinghy under her knees. She could feel Ila's grip on her arm, hard and warm and absolutely steady. She could feel the lift and fall of the water, and a faint grinding crunch, and then the keel slid on shingle and stopped.

Ila's hand squeezed hers, once.

Tamsin scrambled out onto the stones. They were cold and wet and slick with weed. She found Ila's arm and held it. She found the line, and hauled the dinghy up the beach, and the two of them dragged it clear of the waterline by feel alone, panting, soaked, with their hands numb.

She tried to speak.

Nothing.

She tried again, and her throat burned with the effort, and she heard only the quiet thud of her own pulse.

The fog pressed close. It was not cold, exactly. It was a curious damp mildness, soft as breath, and it clung to her skin in a fine glittering dew. She stood on the shingle with her arms at her sides and her boots filling slowly with cold water, and thought: Odo will have signaled. He'll have fired the flare. He'll know we're ashore.

She could do nothing. She could only wait.

A hand slid into hers.

She did not look down. She stood very still, with her heart going like a trip-hammer, and felt the cool damp palm lie against her own. The fingers curled. They were trembling slightly. They held on with the quiet desperation of a person grasping a rope, and Tamsin, who had spent seven years resolutely not wanting anything, found that her own fingers had closed in response.

For a long moment they stood like that on the stones.

Then Ila tugged, once, gently, and pointed up the beach.

* * * The boathouse was a long low shed of weathered gray planks, half sunk in the shingle, with a roof of rotted thatch and a single door hanging crooked on one hinge. It had stood there for a century. It would stand for another. Inside, it smelled of tar and old rope and the faint sweetness of rotting wood, and there was a pile of folded sailcloth in one corner that, when shaken out, proved dry.

Tamsin lit the little lantern from her belt.

It threw a small cone of gold across the floor. She saw cobwebs, stacked crates, a rusted anchor the size of a child. Against the far wall, an old iron stove. Beside it, a heap of driftwood, dry as bone. She knelt and began to build a fire with fingers that were clumsy from the cold, and after a minute, a hand reached past her shoulder and held out a matchbox.

She looked up.

Ila was standing very close, with the matchbox in her palm. Her face in the lantern light was drawn and pale. Her hair hung in dark wet strands against her cheeks. She was holding the box out with a sort of grave, formal courtesy, as one might present a diploma.

Tamsin took it.

The match flared. The kindling caught. A small bright flame leaped up in the dark mouth of the stove, and the whole shed lightened, and the long shadows on the walls began to move.

They sat on the sailcloth with their backs to the planks.

It was a very small space. The stove glowed. The lantern hung from a nail. Outside, the fog pressed against the door like a patient animal, and not a sound reached them from the world, not a gull, not a wave, not the groan of a hull. It was the most perfect silence Tamsin had ever known. It was warm and deep and soft, and it seemed to go on forever.

She became aware of a small hot ache behind her ribs.

She knew what it was. It was the thing she had been carrying for a week, for a month, for seven years, a great swollen knot of questions and accusations that had no outlet. She could not speak it. She could not scream it. The island had taken her voice, and left her only the words.

She looked at Ila.

Ila was watching the fire. Her profile was sharp against the flames, the line of her jaw, the curve of her lashes, the small hollow at her temple where a pulse beat. She had pulled her knees up to her chest and wrapped her arms around them. She looked young. She looked small. She looked, Tamsin thought, like a girl on a beach, in the dark, with a lantern in her hand.

She reached out.

She did not think. She took Ila's hand, the one lying loose on her knee, and turned it palm upward. It was warm. It was slightly rough, with a callus at the base of the thumb where the brass ring sat. The ring itself gleamed in the firelight.

Tamsin ran her thumb across the center of the palm, slowly, and began to write.

One letter. One stroke. She traced it as carefully as a child at a slate. A W. Then an H. Then a Y.

She felt Ila go rigid.

For a long moment, nothing happened. The stove ticked. The lantern swayed on its nail. Ila's fingers lay open and trembling in Tamsin's, and her eyes stayed fixed on the fire, and her lips pressed together, white at the edges.

Then, very slowly, she turned her head.

Her eyes were wet. She was looking at Tamsin with an expression of such naked, helpless misery that Tamsin almost took it back. But she held her ground. She held the hand. She waited, steady and silent, with the question lying between them like a dropped coin.

Ila took her hand back.

She turned Tamsin's palm up in her own, and with a fingertip, light as a feather, began to write.

B.

A pause. The fingertip trembled.

E.

Tamsin held her breath.

She felt Ila's whole body strain, as if against a great weight. A hard shudder ran through her. The fingertip faltered, and slipped, and pressed against the skin so hard it hurt. She drew in a sharp, soundless gasp. Her eyes squeezed shut. A bead of sweat rolled down her temple and dripped from her jaw, and the finger on Tamsin's palm shook, and jerked, and began, laboriously, to trace the next letter.

C.

Then it stopped.

Ila's hand went limp. She bent forward, with her forehead nearly on her knees, and drew in a long sobbing breath. Tamsin could feel her shaking. She could feel the vast, silent, convulsive effort of it, the huge muscular strain of someone trying to lift a mountain with her bare hands.

Because, she thought. Because what?

She did not know. She would never know, if this was the only way. And she thought, with a cold flash of understanding: she can't even write it. Whatever it is. She can't tell me, and she can't write it, and she can't mime it, and she can't. She is not hiding. She is bound.

It was the second time she had thought it. But this time it did not feel like a theory.

She gathered Ila's hand in both of hers.

She did not trace a letter. She did not ask again. She simply held it, with the palm turned up, and pressed her own against it, and bent her head so that her forehead rested lightly against Ila's knuckles. She stayed that way, in the warm gold dark, until the shaking slowed.

Then Ila's other hand rose, and rested, very lightly, on the back of her head.

* * * They slept, in the end.

It was not intended. Tamsin meant to stay awake, as a captain should, to keep watch against some unnamed danger. But the stove was warm and the silence was soft, and the long, wild, emotional strain of the day had hollowed her out like a gourd. Somewhere in the small hours, she felt her head grow heavy. She leaned back against the wall. Her shoulder touched Ila's.

It was not an accident. Neither of them pretended it was.

They sat side by side, with their backs to the planks and their knees drawn up, shoulder to shoulder, in the circle of the stove light. The fire burned low. The lantern guttered. And through the thin wool of her sweater, she felt the whole warm weight of the woman beside her, and thought that she could have stayed there forever.

At some point, the chart began to glow.

She had not meant to bring it. But since that day in the cabin, she had found it difficult to be parted from it. She had strapped the leather tube across her back that morning without quite admitting why, and it lay now against the wall behind her, a long dark cylinder gleaming faintly at its seams. As she dozed, she felt it hum, a low, soft, contented vibration, like the purr of a cat.

She roused, slowly, and reached back, and drew it out.

The chart unrolled across her knees like a sigh.

She did not need the lantern. The parchment itself gave off a pale golden light, and by it she saw the new drawing take shape in the empty space beside the Shoal. A long, curling arc of fine pale lines, like rolling mist. A little cluster of drifting gray ovals. And in the center, drawn in a single flowing stroke, a hand with its fingers outspread.

Beneath it, in her father's slanting script, a line of text.

What is left unsaid is also owed.

Tamsin read it.

She read it again. And then, with a slow, strange chill, she turned her head, and found that Ila, awake, was reading it too.

Their eyes met.

Neither of them could speak. Neither of them needed to. In the glow of the old paper, Ila's face was full of a terror so profound, and a longing so deep, that Tamsin felt the breath leave her body. She saw it all. She saw it written in the slant of the lashes and the tremor of the mouth and the way the fingers curled, helplessly, in her lap. She saw the whole vast silent weight of it, the debt, the burden, the seven-year bargain with the dark.

And she thought, without any bitterness at all: I don't know what you did.

But I know what it cost.

She did not know how long they sat like that. It might have been minutes. It might have been hours. Outside the little shed, the fog drifted, and breathed, and waited. And the stove burned down to embers, and the gold on the parchment faded, and neither of them looked away.

* * * She woke to light.

It was thin and pale and gray, the cold dawn light that creeps in through cracks in old walls. It lay in long stripes across the floor. She was sitting upright against the planks, stiff in every limb, with a crick in her neck and a heavy warm weight against her shoulder, and she did not at first understand what it was.

Ila's head.

She had slept against her. Her cheek lay on Tamsin's collarbone, and her dark hair was spilled across the wool, and one hand had crept up in sleep to rest on the front of her jacket. She was breathing slowly and evenly. She looked years younger. Her lips were slightly parted, and a faint crease marked the place on her forehead where it had pressed against a seam.

Tamsin did not move.

She told herself she did not want to wake her. She told herself it was merely courtesy. She sat very still with the chart across her lap and her own heartbeat loud in her ears and watched the light creep slowly up the wall.

Far away, something rang.

It was a thin, clear note. A bell. A ship's bell, striking the hour, six strokes, bright and sweet, and she felt her whole body go taut with joy. She heard the long cry of a gull. She heard the slap of waves. She heard the soft crackle of the dying embers in the stove, and a rustle of canvas, and the creak of the old walls settling.

Sound.

It had come back all at once, like blood to a numb limb. The world was loud again, glorious, ordinary, noisy. The fog had lifted. Through the crack in the door she saw a swath of white-gold sky and a stretch of pale water, and she heard, distinctly, the deep, throaty rumble of a diesel engine. The Marrow Lark. She would know that sound anywhere.

Ila stirred.

She made a small sleepy noise in her throat. Her hand tightened. Her eyelashes fluttered, and lifted, and her eyes, clear and brown and not yet entirely awake, found Tamsin's face, inches away.

She did not startle. She did not pull back. She only looked, slowly, with a vague, drowsy, wondering smile, as if she were seeing something she had not expected to see again.

And Tamsin, who had meant to say something brisk, something professional, something cool and efficient and wholly appropriate, opened her mouth, and the first word out of it was not any of those.

"Ila," she said.

It came out cracked and soft and thick with sleep.

She had not said it like that in seven years.