It begins mid-Channel, two big winds meeting to force a monumental updraught. Five hundred thousand tons of water vapour hoisted aloft, condensing as they rise to build a cumulus three miles high, the mountain of it sliding over the surface of the sea. The day’s light is dying slowly, tankers and trawlers hardening to crisp black silhouettes on the tide, studded with lights of holly green and cherry red. At forty thousand feet, the summit of the storm cloud spreads sideways to make a grey anvil in the heavens. Cumulonimbus incus. Only the upper reaches are lit by the remaining sunlight as it arcs away around the earth. Crossing Portland Bill and Weymouth, the vast structure heads inland. Miles up, water gathers into drops which turn to ice as they descend, leaving the cloudbase as marbles of hail which clatter against windows and drum on the roofs of cars and smash through the leaves of alder, oak and beech in the New Forest.

The lightning starts inside the summit of the cloud, the heart of the anvil momentarily luminous. Then below the base of the cloud, channels of ionised air dodge and branch downwards until the earth senses them and sends up its own streamers of ionised air and the sky is ripped by great cracks of plasma. Two million miles per hour, fifty thousand degrees centigrade. The sonic boom spreads in a fading ring of crack and rumble. The tang of ozone mixes with the smell of sodden earth in the wet night air.

It is directly above the house now. Logically it should strike one of the innumerable tall trees in the garden or in the surrounding woods, but lightning is rebellious and there is steel rebar in the refurbished parapet which borders the roof and those channels of ionised air connect the north-east corner of the roof to the tonnage of charged vapour overhead and the blinding fire rides its way down the side of the house, splitting concrete from concrete.

Philippe is woken by a loud bang. Was it real or did he imagine the noise? He sits up in bed. Nothing seems out of place at first. The faint blue outline of the armchair, a thin stripe of light between the curtains. Rain drums on the glass. A nightmare. He lies down but he is restless and uneasy and cannot drift off. Something is wrong. He sits up again. Burning. He can smell burning.

He runs to the door and opens it. The landing is an oven. There are curls of smoke in the air and a dancing glow from the ground floor. He shields his face and looks into the stairwell. He can see flames. It is no longer possible to go downstairs. The heat is unbearable, even at this distance. If the nurse does not rescue her then Angelica will die. A sick panic overwhelms him. How will he live with himself if he did nothing to save his daughter? But in the middle of his horror he sees an opportunity to escape a terrible quandary. If Angelica dies then she will take her story to the grave. She can no longer destroy them both. One of them, at least, will survive and be able to fashion a kind of life. She is unconscious. She will feel nothing, know nothing. It will be a blessing.

He coughs violently. The air is filled with soot and black flakes. His head swims. And only now does he realise that he must act fast if he himself is going to survive. He turns and climbs to the half-landing, unlocks the door and steps out onto the flat roof, shutting the door firmly behind him. He will be rescued. He has always been rescued. He walks to the front of the building and looks down. He can see no one. Then a rising curtain of smoke and heat-rippled air forces him to back away from the edge. He crosses to the other side of the roof and looks down the valley where the road winds up from Braishfield. He can hear no siren. He can see no blue lights. The roof is growing warm under his feet and he can smell the heady stink of the bitumen as it starts to soften. He is three storeys up. Below him is a four-metre band of concrete before the lawn begins. If someone is coming they will not get here in time. He must jump if he is to stand some small chance of surviving. He cannot bring himself to jump.

Downstairs, Angelica lies at the centre of the web of tubes and wires that keep her connected to the world. Cannulas, monitor, drip stand, oxygen tank. The pillows are banked behind her so that her head remains elevated. She is wearing a sky-blue blouse smart enough for a champagne reception. A mohair rug lies across her lap and legs, rainbow spots on a grass-green background.

No one will see this room again. No one will see the two Edward Ardizzone sketches of children playing on a beach. No one will see André, Angelica’s toy rabbit, now worn a little thin in places, sitting slumped against the CD player. No one will see the charm bracelet which once belonged to Angelica’s mother. No one will see the porcelain bowl on the base of which a porpoise is pictured, mid-leap, above a jumble of intricate waves.

The air is hot and foul but for now the bedroom door is holding back the furnace which rages in the stairwell. Grey smoke pours from the gap at the foot of the door, then flows upwards and pools on the ceiling. The centre of the door blackens and blisters and bows inwards. Emaciated and bone-white, Angelica dreams of porridge and apricots, of yew trees and pale stone, of fox cubs tumbling over one another in the corner of a garden.

Philippe jumps. He clears the concrete and hits the grass, but the impact shatters both his legs. Using the very last of his energy he crawls away from the inferno into the relative cool of the trees at the edge of the lawn, but the breaks are open and over the next fifteen minutes he will bleed out among the pine needles and the dead branches. The fire brigade will assume that his body has been incinerated completely somewhere in the house and his corpse will not be found for another three days when Hervé is showing the insurance agent round the devastated property.

Back in Angelica’s bedroom the smoke on the ceiling is getting steadily thicker and lower. The windows are now coated with the soot and the only light comes from the monitor above the bed. The air reeks of burnt wood and melted plastic. Angelica no longer has any reason to remain alive. Her life is a burden she wants to put aside. But the animal body will not give in so easily. With her right hand she tears the cannula from her arm, grips the stainless-steel rail which runs along the edge of the mattress and hauls herself upright as if she could simply get to her feet and walk away. But such a thing is not possible. Such a thing has not been possible for months. Her fingers loosen, her grip fails and she collapses back onto the pillow. The green sawtooth line running across the monitor’s screen goes flat. A red light flashes but the whining alarm is inaudible over the growing roar. On the far side of the room the door is punched from its frame like a playing card and flames pour in from the landing.

A woman is standing beside the bed. Tunic, boots, quiver. She seems familiar but Angelica cannot remember when or where they last met. The woman reaches out. “Come. Take my hand.”