He told his friends he was preparing for Armageddon, but really he just liked to get away from his children.

Retreating from their shrieks, he relaxed by contemplating doomsday scenarios.

In their garden he would build a bunker in which to shelter from the end of the world.

He researched online: original plans for Anderson shelters; catalogues that pandered to survivalist cranks.

As he trawled apocalyptically, he found startling images.

He encountered cities built that they may be destroyed, replica towns constructed for military rehearsals, landscapes initially bullet ridden, subsequently bombed, before full-scale annihilation as technologies advanced the manner of war.

Oddest of all, he stumbled upon savage beauty pageants.

In the fifties, holidaymakers had made for sites on the edge of nuclear testing grounds. Drinks in one hand, binoculars in the other, guests scanned the horizon for bomb blasts. Hotels, capitalizing, threw themed parties — the naïve drinking explosively named cocktails, lurid and tasteless — climaxing in the crowning of Miss Atomic Bomb. Black and white images, at once benign and terrifying, showed pretty girls in cotton-wool mushroom-cloud swimsuits.

Wistful, he considered couples fucking as bombs exploded: men promising the earth would move; young women persuaded out of their mushroom-clouds. Beside beds: cotton-wool fallout. Could he rouse the blood with the apocalypse upon him? Likelier he would wilt under the pressure of this last chance tango, a now or never tremble, an impotent twitch as the switch was flicked.

In the garden, he tunnelled corewards.

To his children, he explained that he was building a den. This piqued their interest, but he knew that it would evolve too slowly for them. This was no sheet strewn over armchairs, no flimsy fortification.

As their father busied himself digging, they retired to less exertive fantasies.

It was the latest in a long line of home improvements. His wife was accustomed to his absences. His ramshackle sanctuary would take its place beside other tinkerer's paradises — the garage, the shed, the allotment — myriad hobbyists hiding from their lives.

A hole became a ditch, became a trench, became a home from home. Soil shored, substantially buttressed, he constructed his place of safety, his secret chamber.

Having burrowed deep underground, he hoped to counter all manner of catastrophe.

Dismissively, he read of flippant hipsters preparing for zombie attacks, their properties fortified against the undead. Newly risen corpses were the least of his concerns.

His shelter would hold steady against less fashionable apocalypses, the classics: air raid attacks, nuclear winter. It would not fare well in a flood, but then he had no desire to live in a waterlogged future.

He pictured his children, drowned like unwanted kittens, bobbing in stagnant water.

In the evenings, his haven was finessed, by night, road tested. He did not wish to discover structural troubles once the undefined end was nigh. He would not breathe his last, painfully, in a soil-choked mausoleum. Slumped in discomfort on a sandbagged seat, spooning food from tins, he transported himself back in time. Preparing to live off-grid — the future would offer no electricity — a treasure chest of candles would see him through dark times.

His house became a blur, a corridor from the street to his subterranean refuge.

Decoration was minimal, interior design an affront to his goal. They would not survive in stylish isolation. In austere surroundings, they would awake to a new dawn.

He amassed imperishables, tinned sustenance, provisional pyramids. As a family unit, they would not sink to cannibalism.

Suitably entombed, his thoughts turned to pharaohs. He considered twenty-first century burial essentials. A life's artefacts were now ephemeral, lives stored in inaccessible clouds. Survivors would fail to be reconnected with their electric memories.

What would happen if the end came whilst he was at work? He felt it better not to stray from safety.

He took to working from home.

He moved clothes over to the shelter.

Eventually, thankfully, he was relieved of work worries.

Retreating from life, he huddled underground. He lived predominantly below the surface, mirrored gold reserves, the dead and toxic waste. It was, he conceded, mixed company.

Through dubious connections, he had equipped himself with a Geiger counter. He would know when it was safe to surface in his brave new world.

He was not the wilderness type, a bedraggled desperado desperate to lay waste to an imagined opposition. No rifle would rest tense in his arms, his finger itching to despatch invaders. He was not pitting himself against the world; he was simply taking precautions.

Though in thrall to nostalgic paranoia — air raid sirens, three-minute warnings — he knew that any future annihilations would offer scant opportunity to prepare. There would be no timeline animation of a missile in flight, tweets briefing followers, impending death condensed in rash capitalisation, hashtags and exclamations marks. This would be an instantaneous blitz.

He would have to make his shelter his permanent home if he was to avoid the worst of it.

Whilst there was room enough for his family to survive alongside him, they seldom joined him in his ongoing rehearsal, shunned such claustrophobic gatherings. They had no wish to suffocate in each other's company. Accustomed as they were to running water and electricity, it was not their idea of a good time. I have no desire to be your Eva Braun, his wife told him. They left him alone to his candlelit sensibilities.

In the mornings, he would surface, squinting, mole-eyed.

One morning he awoke to find his house deserted. He scoured room after room, but there was no trace of them. What manner of catastrophe had snatched them from him?

Surveying empty rooms, he felt the first twinge of survivor's guilt. He moved towards the fridge. Contemplating his loss, he retrieved supplies. He would need energy to go on.

Morose, balancing snacks, he made his way back underground.