David gazed across, and he felt his heart shrivel in bitter disgust. Amy had a hand to her face, shrouding her tears.

Two corpses were sitting in two chairs.

José and his wife.

Fermina Garovillo had been shot at close range through the temple, the side of her head was simply missing; the obscene wound was echoed and amplified by a splattered patch of blood on the wall nearby. José had shot his wife first, it seemed – and then turned the gun on himself. And his wound was worse: the entire top of his cranium, taken clean away. Burn marks on his thin white lips showed how he had done it, put the gun between his teeth, pulled the trigger – blasting away his own brains.

More blood on the ceiling and the wall behind confirmed the suicide. David took one quick look at the grey jellylike stuff balanced on top of the chair – and he felt the rising bile of nausea.

But why?

Why had they done it?

An answer, the answer, came immediately. The menacing slurch of tyres, outside.

David went straight to the window and scanned the scene, his muscles tense with alarm. And there. There it was. The reason for José and Fermina’s suicide, maybe. A red car, driving slowly between the dripping trees. Miguel was surely inside the car. David recalled old José’s words. One day he will kill me.

Amy joined David at the window. She cursed and shivered, simultaneously.

But there was faint hope. The red car slowed to a stop, then it started up once more, going the wrong way. David realized, with a tiny jolt of optimism, that Miguel must still be looking for them. The Wolf didn’t quite know where it was, he was driving up and down. For how long he’d been doing this, who knew. However he had discovered their exile in Campan – torturing Eloise maybe? – he hadn’t pinned down the precise location of the refuge.

But it wouldn’t take him long. Eventually he would see the concealed turning. Miguel would drive past the bushes, and look in the right direction. And then discover the house. And then come and kill them. Epa. Epa. Epa.

‘The gun!’ said Amy.

‘What?’

‘There must be a gun.’

She was right. David scanned swiftly around the room for José’s gun. The old man must have had a gun to shoot himself and his wife. And there – a glimpse of black metal in the greyish light. David reached between José’s lifeless legs and picked up the pistol. It was still warm. He figured there must be bullets left inside. There had only been two gunshots.

He lifted the gun and held it, pointing the muzzle at the ceiling.

For a second the madness of it all gyred in David’s mind: a year ago he was a lethargic media lawyer. Bored, safe, and incoherently sad. Commuting on the District Line tube, going home to a microwave chicken curry, maybe a pint with a friend. Maybe meaningless sex with someone he didn’t love, if he was lucky. Now he was terrified, and angry, and hunted – and yet the paradox was there again: he felt more alive than ever.

He wanted to live now: he wanted to live so much. To find out the deeper reasons for his parents’ murder, and to take revenge for their deaths. But the first thing was to escape.

‘The back garden,’ said Amy, her tears visibly repressed. She was being strong, she looked angry. ‘Through the garden, the ravine? We can go that way?’

They hurried out of the door and along the hall; the damp old planks thudded and creaked as they took themselves downstairs, to the rear of the house – from there the garden and the gate led to the forests; but Amy pulled him back.

‘Listen!’

He listened; she was right. Voices. Out there in the garden, maybe over the wall – in the woods.

‘We can’t risk it,’ she hissed. ‘The road?’

‘Miguel’s car.’

They sighed with frustration – and fear. David felt the rage inside. ‘We’re stuck. Dammit we’re just stuck. He’s got us trapped!’

‘No. The cellar!’ She grabbed his arm. ‘I am sure there are passages down there. C’mon, we have to find them.’

She turned, and they ran down the musty hallway – and turned right. There was an old cellar door under the stairs. David reached for the handle.

The subtle growling of a car engine was distinct. Somewhere out there in the rain and the ruins the car was coming very close, prowling past the old cottages of the Cagots, taking the turning that led to the hideout. The voices outside, in the woods at the rear, were still audible. Closing in.

The door to the cellar opened on a dingy set of descending stairs, plunging into the dark dark underworld of the Cagot refuge.

They had no choice. David followed Amy down the steps, into the blackness. He turned and shut the door firmly behind them, immersing them in even deeper darkness. It felt like drowning at night.

‘Amy -’

‘Yes!’

‘You’re OK?

‘Here’s the floor…I think.’

David took out his phone and switched it on and used the light of the screen to see; the feeble glimmer illuminated the echoing black cellar. He surveyed the gloom.

‘Wait.’

Amy had a finger to her lips. They stood still, and mute. Frightened. Male voices were discernible. Inside the house.

‘The vaults!’

David squinted. Now that his eyes were adjusting, he could see the true size of the cellar. It was enormous – high ceilinged and enormous, stretching into the dark, a real medieval dungeon. Somewhere for storing a lot of food, maybe, when the Cagots had to hide out.

Giving off the main vaulted cellarspace was a series of massive wood-and-metal doors, leading, it seemed, to more dark, clammy chambers. Three of the doors were open, two closed.

‘We need to search – the spaces -’

They peered into the first vault. It was so cold and sticky in this secondary cellar, their breath hung in the air, the spectres of words. David flashed the phone-light around. The goose’s foot was carved on the lintel. The mark of Cain. David turned his light quickly this way and that, but the space was empty. A narrow stone bench ran along the side, empty. The smell was faintly rancid.

More noises scuffled upstairs. Then the thump of boots on stairs. The men were searching the upper floors of the house. They would find José and Fermina. That might delay them. David tried not to speculate on Miguel’s reaction. He would come upon the grisly sight of his self-murdered parents: he would be more angered than ever before.

And then the terrorist would realize, he would descend. And find the cellar door.

Trying to quell his panic, David paced to the next vault. The second one was like the first, empty, long and obscurely pungent. His anxiety was like a drumbeat. Accelerating.

He stepped further inside, ensuring there was no concealed exit. There wasn’t. The third vault was the same: it had no other doors. Now Miguel’s dark voice could be heard – in the hallway above. Shouting. Soon he would see the cellar entrance.

They had come to the fourth and penultimate vault. It was sealed. The metal door was tall and mossed over with decay.

‘Try it!’ Amy whispered. ‘We have to -’

‘Hold the light -’

Amy took the phone and poised it – as he tugged, fiercely, at the cold metal handle. He tugged harder, and then again, even harder. The door began to slide, very slowly. It wheezed and complained, slowly yielding to his desperate struggles. The metal grated resentfully against the stone – and then it seemed to explode: it fell open and a swamping deluge of brown and rancid fluid came after, a wave of thick and malodorous soup that was so fierce it knocked them both to the cellar floor.

They were slipping now, slipping and gasping in the slimy water; and David could see, knocking and bobbing in the subsiding floods: yoghurty flaps of flesh, and grimacing human heads, and fibrous, amputated arms; the heads were half decayed, the hair on one face was like rusty brown wire; a protruding arm bone was sticking out of leathery strings of muscle -