Scorpio is not even on the radar as I shiver. Certainly for yours truly, slipping into Earth-side retirement after all but dying beyond Jupiter’s ice-moon, Europa. That would have been a quick death, thanks to the efficient vacuum of space. Now Scorpio seems the only answer to a slow death.

But I get ahead of myself.

Icicles hang halfway to the Avon from the underside of the bridge. A metre of snow hides the motorway that it carried, abandoned before I was conceived. The bridge has now followed the road into neglect. It will decay to the sad fate of its sisters that used to span the Estuary ten kilometres north. There, truncated, rusting pillars poke through the sheen of the Severn, still frozen and glistening under a May sun.

Between, Avonmouth crumbles into its grave. The scene below me, Edmund’s birthplace of Pill, is hardly less desolate: what roofs still survive, sag under layers of snow. The odd plume of smoke discloses some brave soul still toughing it out, still clearing a path to his door, still keeping drifts trimmed to below gutter level. The brief sun slides back into the grey blanket above us and feeble lights glow from these exposed windows.

God knows why Edmund’s brought me here. It’s not like I’ve never seen icy vistas. Europa has enough for a lifetime.

“OK, pal, you can reseal the craft,” I say. “I get the subzero temperature idea.”

Instead he slides the vehicle higher to view the surface of TransHub. It breaches this side of the Estuary, in the middle of the King Road. From it, steam vents, panels glitter and masts sway in a slight breeze. Stretching away downstream the submarine depot sends us distant bangs, thumps and rhythmic tapping. Civilisation. Also clinging on.

“Good idea,” I say, “back to base.”

“Not yet, old chap. You need to see more.”

I’m thrilled.

Edmund banks us round to follow the Avon upstream. For a medico he flies like a natural – the flying doctor.

“I’ll come clean,” he says. “I want to change your mind about resettling on good old Planet Earth.”

“You’re a persuasive bugger, but not that good. I’ve had it with Space.” I feel tremors starting at the very mention.

“We’ll see.” He winks at me. “Modern medicine, old boy, we work wonders. Unlike the planetary doctors. Look below.”

The river – perhaps I should say glacier – is spilling out of the famous Gorge. Actually it’s filling the ravine with ice. It wasn’t doing that last time I was here… what, twenty years ago? It was cold that summer but not icy.

Edmund has us at cliff-edge level. I expect him to climb over the Suspension Bridge.

No need. The stone pillars are all that remain. And beyond, what looks like a skating rink with frozen cubist sculptures for skaters.

“That’s… Bristol?” I manage.

“That’s the reality. Not the selective feeds you had on Europa.”

We keep a decent height and approach the Daliesque scene. The sculptures resolve to tower blocks squeezed into collapse by the advancing glacier.

It is a glacier.

“Are there many of these?” I ask.

“This is the vanguard but there’s no escape. There’s not much of England’s green and pleasant left to stand upon, far less in Scotland.” He brings us to a stop, facing a tower on a hill, still intact above the devastation. “Remember what that is?”

I don’t need to: I carry an encyclopedia in my head. The Cabot Tower.

Edmund’s filling me in anyway: “…sailed his ship, the Matthew to the New World, refuge for the dispossessed of Europe –”

“Very nice.”

“You don’t see the parallel?”

“I’m sure you’re going to tell me.”

He doesn’t. He sits and stares and lets me work it out. He knows I’m not stupid.

“Right enough, what’s your answer?” I say.

Edmund shrugs. “The same as your parents.”

I haven’t thought about them for a while and that familiar catch in the throat takes me unawares. I gulp and ask, “Thirty years on, eh?”

His silence is answer enough.

Still I have to ask, “Another fleet of arks to Chara?”

A rattling startles me. Hailstones spatter our craft and a wind whips up from nowhere. The flyer lurches once then calms as the autopilot adjusts. The squall obscures our view of Cabot.

“Strictly hush-hush.” Edmund’s voice is perversely raised against the racket. “But the latest target is Scorpio. 18 Scorpii to be precise.”

I’m way ahead of him now. The data on that obscure little star in the constellation flashes through my mind.

“Third planet out,” he shouts.

I have it – Earth-like, and more so than Chara, according to recent probes. The data is there if you look for it.

Edmund’s still in the background: “…the news will break soon but best to get ahead of the game –”

“And you’re telling me, why?”

“Keeping it in the family. Looking after our own.”

I don’t buy that but I don’t say it either. An extraordinary few will escape the slow death of the planet and I know he knows how much value is locked up inside me.

“Think about it, old boy,” he says.

That was yesterday and now, here in TransHub, back under the Severn, in my metal cube that passes for a living space, Scorpio won’t stay off the radar. I look at Edmund’s model of the Matthew and wonder how I would handle Space again.