They found the wrecked boat when the line was almost fully paid out. Philippe had been swinging his lights from side to side and, at the extremity of one sweep, they both saw something white flash against the darkness, on the lake floor. When the beam returned, it showed a straight white line; an edge of some sort. It looked artificial, something shaped by humanity. Philippe pointed, looking back. She nodded. The orange line made a perfect curve as they swooped towards the white triangle.

The boat was six or seven metres long; open, with no sign of a mast or rigging. It was fibreglass, and it lay, without any obvious sign of damage, flat upon the floor of the lake. There was a layer of mud inside it, perhaps a quarter of a metre deep. She wondered how long ago it had foundered, and how accurately you could date its sinking from the depth of mud inside. It had, probably, been a fishing boat; a few pieces of string or line moved like tendrils in the mud within its bows, and some netting protruded from its centre-line, waving in the water like odd, graphed weeds. Philippe moved to the boat's stern, and found its outboard motor, missed initially because it was black and comparatively small. He pointed enthusiastically.

Then, like the sound of a ghost, she heard an outboard. She stiffened, felt her eyes go wide. A brief panic seized her and she struggled for breath. She breathed, listened. Philippe still didn't seem to have noticed; he was inspecting the drowned engine.

Whirr; a shrill, distinctive noise, burbling in her ears. She shook her head but it was still there. It was a relief when she saw Philippe look up, his face behind the mask looking surprised, even shocked. She nodded and pointed from her ear to the surface, then at the outboard he still held.

The noise came closer. She thought she could hear not one high-revving propeller, but several. Philippe gestured hurriedly at her, fiddled with his lights, gesticulating at them. They blinked out. She realised immediately, and switched hers off.

The darkness was absolute. The moon was only a sliver, and the clouds had moved over in late afternoon, blanketing the skies above the lake. The ships were a kilometre or more away. She was blind. The water moved round her limbs, the lights felt weightless in her hand. She let go of them, just to feel the slight tug on her wrist as the lanyard tightened, gently trying to pull her to the surface. Then she pulled the lamps back again. The prop noise swelled, like something angry. and vindictive; a drowning whine.

A dark force seemed to gather in her throat, as though a sea snake had wrapped itself round her neck. She fought it, struggling to breathe again, trying to concentrate on the high, gargling sound of the approaching boats, but the feeling increased, blocking her air passage, making her gorge rise. She brought her hands up to her mask, to her neck. Nothing there; nothing round her neck.

Hisako went limp, relaxing, giving in to whatever it was.

She hung there, arms limp, one hand hanging at her side, the other hand raised over her head by the slightly positive buoyancy of the lights, her legs dangling and her head down, on her chest, her eyes closed.

Slowly, the asphyxia started to loosen its hold on her.

She wondered if she was sinking or rising.

tic tic tic.

Ah.

The noise of the boats peaked and passed. Her flippers met the soft mud of the lake bottom, and she kept on going down, her legs buckling slowly, knees folding. She felt the cool mud waft up around her thighs. She stopped like that, in equilibrium.

There. She tested herself, taking a few deep breaths. No problem. Hisako opened her eyes, looked around at nothing but darkness. She brought her watch up, to make sure she could still see as well as to check the time. The luminous face glowed dimly at her. They'd only been down ten minutes; lots of air left.

The sound of the outboards cut suddenly. She brought her lights down so that she could grasp them again.

She tried to remember which way the foundered boat might be. Perhaps she ought to search for it, try to find Philippe. But she might get it wrong; head off in the wrong. direction. She could try going in ever-increasing circles, until she found the line that led back to the boat… if she didn't swim under or above it.

She could kick to the surface; it was calm and she would be able to orient herself by the moored ships and find the Gemini. But whoever was in the boats that had gone overhead and then stopped might see her.

She would wait here for a while; for ten minutes. Or until she saw Philippe's lights again, or heard the boats move off. She undid the pop-fastener on the big diver's knife hanging at her hip, as much to reassure herself she was doing everything she could do in the circumstances as to ready herself for a fight.

She knelt in the soft mud, submerged in darkness, breathing slowly, looking around every now and again.

The high whine came again after seven minutes; one outboard, then two… perhaps one more. She turned her head in the direction the noises seemed to come from. She'd wait till they disappeared entirely, then give it another minute before turning on her lights.

A light! It was far away, twinkling like a tiny drowned star, but it was real; blanked out by her hand, and disappearing when she blinked. She kicked once out of the mud, then again to free herself from its slack grip. She swam towards the light. It disappeared, wobbling and dimming then extinguishing, but she kept towards it. It reappeared, a little stronger this time, and started to resolve into two lights, not one. It dimmed, all but disappeared. And then came back; definitely two lights. She swam on, brought her own lamps in front of her.

She was about to put them on when she thought, What if it isn't him? She hesitated, kicking less powerfully, though still. heading for the twinned, distant glow. Finally she brought the knife out of its sheath and held it alongside the lights in front of her.

She switched them on.

The lights in the distance started to dim again, then jerked back, wobbled up and down. She did the same. It had to be Philippe. She kept the knife where it was.

Philippe turned the lights on his own face when she was about three metres away; Flooded with the relief, she copied that too.

She swam straight into him, ramming him, hugging him, lights floating, knife clenched awkwardly in her fist, trying to keep it away from his back and his air hoses.

'I don't know, he said, when they'd kicked to the surface. She could just make out the white smudge of his face. 'But they had no… navigation lights? I think military. I… she thought he was going to say something more, but he didn't.

They bobbed in the water, directly above where they'd met. She sheathed her knife, looked towards the trio of distant ships. She listened for the noise of outboard engines, but couldn't hear anything.

'Where were you? Where did you go? she asked.

'I swam up; towards them, he told her. 'I heard them talking, but it was… espagnol.

'What now? She spat some water out, looked round for their Gemini.

'Back to the ship. He looked round too.

'I lost the line, he said. He nodded in the direction she was looking. 'You think that way to the Gemini?

'I think so.

'Me too.

They set off keeping the ships to their right. She was waiting for an explosion; a sudden flare of light, a livid mushroom cloud from Le Cercle, or a burst of gunfire, the water leaping around them, a sudden sledge-hammer blow to the exposed back of her skull… but they swam on, the noise of their own progress through the water the only sound.

A glint in the distance, a little to the left. She squinted. There; again. 'Philippe-chan, she whispered. 'Over there. She moved to him and pointed, lining his face up with her arm. The tiny glint again; perhaps the ships' lights reflecting on the glistening hull of the inflatable.