The first things you notice about Slaughterhouse-Five are also the last things. “All this happened,” the narrator begins, putting everything else that will follow into the past tense. Then he tells us that a guy he knew “really was shot in Dresden for taking a teapot that wasn’t his”. The book ends in more or less the same place, give or take a bit of birdsong: “Edgar Derby was caught with a teapot he had taken from the catacombs. He was arrested for plundering. He was tried and shot. So it goes.”

It’s funny that Vonnegut cues us up for the story of poor old Edgar Derby getting shot right at the start, only to tell it all in a rush, right at the end. But, like most of Vonnegut’s jokes, this one isn’t half so nonchalant as it first seems. The quick and casual way that Vonnegut dispenses with this major character seems completely in line with how death has been dealt to so many others in the chaos around Dresden. One last time, we’re reminded of the futility of war.

The circularity of having the end in the beginning also fits neatly with the overarching narrative, where everything is out of conventional order. The story loops back on itself; later scenes echo earlier ones in curious ways, ideas keep recurring and most events are not shown chronologically. It can feel almost random – although it would be a mistake to think it is disordered. Nothing in Slaughterhouse-Five is casual.

Vonnegut’s careful scheme for this novel is in part explained in its full title, which runs:

Slaughterhouse-Five or The Children’s Crusade

A Duty-dance with Death

A fourth generation German-American

now living in easy circumstances

on Cape Cod

(and smoking too much) who, as an American infantry scout

hors de combat, as a prisoner of war,

witnessed the fire-bombing

of Dresden, Germany,

“The Florence Of The Elbe”,

A long time ago,

And survived to tell the tale.

This is a novel

somewhat in the telegraphic schizophrenic

manner of tales

of the planet Tralfamadore,

where the flying saucers

come from.

Peace.

The alien Tralfamadorians, who apparently kidnap the novel’s hapless hero Billy Pilgrim, see time differently than humans. They see “all time as you might see a stretch of the Rocky Mountains. It does not change. It does not lend itself to warnings or explanations. It simply is.” Instead of a linear chronology, they see a series of moments – just as we do when reading Slaughterhouse-Five. The Tralfamadorians tell Billy that he is trapped in each moment “like a bug trapped in amber” and that it is therefore foolish to talk of cause and effect: “There is no why.”

Just the kind of fun you might expect a science fiction writer like Kurt Vonnegut to indulge in – but there’s more to it again. That idea of there being no “why” and therefore no blame must seem especially comforting to Billy after the war, when you might otherwise expect him to be burdened with survivor’s guilt. Billy has seen dreadful things. Not long after the war he is hospitalised and meets a character called Eliot Rosewater who has also endured horrors in the war and shares his SF novels with him. We are told: “They were trying to reinvent themselves and their universe. Science fiction was a big help.”

As well as a coping mechanism, it’s also possible to see Billy’s time-hopping as a symptom of what we would now diagnose as PTSD. He is, to borrow an image Vonnegut uses early on in the novel, “a pillar of salt” – like Lot’s wife, always looking back and always stuck in that moment. In Billy’s head, the war is ongoing – and so in the book we keep seeing moments from the war, long after we know Billy has returned home. We are told: “Among the things Billy could not change were the past, the present and the future.” We are also told: “There would always be wars.”

Vonnegut’s narrative structure may defy conventional chronology, but emotionally everything falls in just the right place. The war passages build steadily towards the bombing of Dresden, the horrific aftermath, the catharsis of the one horribly sad moment when Billy cries – and then the pointless death of Edgar Derby. The passages after the war have a similarly steady beat towards Billy’s own demise, as well as a kind of understanding of where he might be getting his ideas about Tralfamadore. It may all be, as Vonnegut says early on, “short and jangled” - but it is also ingenious.