John Christopher’s novel, The Possessors, is (among other things) a metaphor of imperial reversal, in which Westerners have the tables turned on them and become colonial victims of space invaders. Christopher’s fantastic Tripods Trilogy also flips colonialism, this time more specifically focused on Christopher’s native England.

Christopher’s “The Long Winter” from 1962, though, seemed like it would be different. I’d heard that it was an apocalyptic tale of a new ice age. No invading aliens; no imperial metaphor.

Shows what I know. The Long Winter is indeed about a new ice age; due to some typically vague scientific gobbledygook, the sun’s rays start to weaken, temperatures plummet, and the British isles, not to mention a large portion of the rest of the world, becomes so cold as to be virtually uninhabitable. Fuel stocks are used up, food becomes scarce, and civilization quickly and efficiently collapses into savagery.

But all of that is really just a set-up for the heart of the novel — which is an elaborate, gleefully mean-spirited excuse to shuffle the English center and the colonized periphery. As Britain disintegrates, all those who can flee desperately to warmer climes — especially Africa. The influx of wealth in that continent creates a new, flush black upper-class. The white immigrants, meanwhile, have, in most cases, lost everything, and become a despised, racial underclass — living in filth and poverty, eking out menial jobs as maids or laborers or prostitutes.

Christopher’s detailing of this reversal is both remorseless and brilliant. In one sequence, the protagonist Andy and his lover, Maddy, having just discovered that their currency is worthless, spend a night on a Nigerian beach rather than pay for lodging they can’t afford — only to be almost arrested under a newly passed white vagrancy law. In another passage, Christopher describes several white boarding school boys talking among themselves with a “fencing unsureness…[a] glib pretense of acceptance into a society which, they knew at heart, would always deny them.” Andy, overhearing them, connects their attitude instantly to that of some Jews he had himself known at boarding school in England.

What’s best about the book, however, is that Christopher is smart enough about the workings of empire to know that it can’t simply be inverted. Oftentimes, narratives which flip power relations simply assume that those on the bottom will behave like those on the top if given the chance. The “moral” ends up being that everyone would misuse power if given the chance — which may be true, but is certainly banal.

Christopher, though, knows that empire can’t be separated from history. Africa in his world is on top…but it wasn’t always so, and that fact matters a lot. Whites may be discriminated against just as blacks used to be, but the exact inflections of that discrimination are slightly different. Sometimes, this difference makes the whites’ situation even worse. Many of the Nigerians that Andy meets clearly relish the Europeans’ come-uppance — they remember suffering under the English boot, and they are eager for payback.

In other ways, though, the legacy of colonialism is a boon for the fallen Europeans — or at least gives them more options in some situations. Andy’s ex-wife, for example, is able to attach herself as a mistress to a wealthy Nigerian in part, Christopher implies, because European beauty standards remain in force. Similarly, many white men who served in European colonial armies are wanted as trainers by the Nigerian military, which is perpetually preparing for war against the white regime in South Africa.

Perhaps Christopher’s smartest reversal, though, is saved for the end of the book, when a Nigerian expedition travels north to colonize England. Andy goes along on the expedition, which is (after some power struggles) led by his Nigerian friend and benefactor, Abonitu. Abonitu repeatedly says that Andy serves as a kind of totem; a sort of living good luck charm. In some ways, this mirrors the manner in which European narratives often rely on a magic Negro — a black marker of authenticity, who provides the hero with spiritual, earthy wisdom. Andy, however, serves a slightly different purpose; he is not a marker of authenticity, but rather an icon of empire. He represents the shining white city of civilization, the position Abonitu, and Nigeria, is trying to occupy. Abonitu dehumanizes Andy, but the dehumanization functions differently than the way that, say, Tonto is dehumanized. Power is inflected by history; for the Nigerians the magic of conquest is not a seductive, humid heart of darkness, but a seductive, cold heart of white. Thus Abonitu describes his desire to take over London:

“I am excited by the idea,” Abonitu said. “And disgusted with myself, a little. When the princesses and queens of ancient Egypt died, they used to keep the bodies until putrefaction set in before handing them over to the embalmers. That was because they found that otherwise the embalmers used them for their lust. London is a dead queen.”

But London isn’t quite as defenseless as a dead queen. Again, history matters; the English — who, after all, still have modern technology, including guns — are able to fend off the Nigerian invasion. On the one hand, I enjoyed the way that Christopher made Abonitu so much more appealing than the English, so that you (or at least I) end up essentially rooting for the colonizer. But still, it is hard to avoid noticing that, in his imperial set pieces, Christopher pretty much always finishes up with a happy ending in which the plucky English throw off their oppressors. However clever his reversals, and however clearly he sees their hypocrisy and their faults, Christopher’s English background is determinative — his people still, somehow, always have to be the good guy. Even if you know how history works, I guess, it’s extremely hard to keep it from working on you.