The photograph at the beginning of this devastating book shows what may have been the last gathering of the Vienna-based family of Gustav Kleinmann, upholsterer. In 1938, during what Austrian Jews would later bitterly name “the November pogrom” – it began with Kristallnacht – peace-loving Gustav, a decorated war veteran, and his son Fritz, 15, were rounded up on the eager testimony of their non-Jewish neighbours.

A year later, Gustav, after failing to rescue his boy from a second arrest and instant deportation – the Kleinmanns’ crime, on both occasions, was to be Jewish – was snatched at night from the family home he had courageously refused to abandon. In October 1939, he was dispatched to Buchenwald. And so, by a freak of fate, was Fritz.

Doubtless, in the awful history of planned genocide we know as the Holocaust, other family members found one another and clung together during a pilgrimage through the rapidly multiplying work camps and extermination sites of Germany, Poland and Austria. Few can have recorded that story with such defiant care as Gustav Kleinmann.

Somehow, throughout five years of methodically vicious incarceration, Gustav (his inspiration during the starvation he continuously endured was Gandhi) managed to maintain and conceal a sparsely kept diary. This journal, published with Fritz’s memoir as The Dog Will Not Die (1995), forms the bedrock of Jeremy Dronfield’s novelistic retelling of those terrible years.

For a reviewer, it feels almost indecent to dwell upon the horrors inflicted, day by day, month after month, upon the innocent. Bizarre details stick in the mind: the meticulously kept flowerbeds; the garish Teutonic halls built for the enjoyment of thuggish guards by an army of slaves. At Buchenwald, Goethe’s Oak, located along one of the great writer’s favourite walks, was put to regular use for crucifixions. A hill nearby, once used for deer hunts, became a hunting ground for men. (Tricking prisoners to cross an invisible boundary line by a tossed cap made them fair game. “And the fool runs,” Gustav noted; each corpse won three days’ holiday for a trigger-happy guard.)

Ironies abound. While intellectuals and artists were ordered to gather shit in gloveless hands, applause was given when one sturdy young journalist managed to hurl rocks faster than the stone-crushing machine revved up to double time (in order to grind its victim down). His reward? A command to act as secretary to the illiterate kapo who had tried to kill him. Gustav, meanwhile, was ordered to join a choir, drowning out the shots being fired at Russian prisoners of war.

It was when his father was abruptly moved from Buchenwald to Auschwitz that Fritz Kleinmann took the most momentous decision of his young life. Licensed to remain in relative safety, he requested to join Gustav on what both men believed was a journey towards certain death. (“Everybody says it’s a one-way ticket, only Fritz and I don’t mope... you can only die once,” Gustav wrote.) The worst, as this theatrical historian never forgets to remind his readers, was yet to come.

Mauthausen was the destination towards which father and son were going when Gustav persuaded Fritz to leap from a train
Anyone new to Auschwitz history may be unaware, as I was, that one of its objectives was to set up a local camp at Monowitz that would harbour a workforce to speed up the building (for the flagging war effort) of a nearby chemical factory. Monowitz, when Fritz and Gustav arrived, was a fenced and mud-sodden field of sheds – no kitchen, no sanitation, no heat – to which they were marched for three hours each day before working on the uncompleted factory. Here, swiftly identifying their skills in bricklaying and stitching, the Kleinmanns stayed alive while up to 150 of their less useful comrades went off each day to be gassed at Birkenau (Primo Levi was another survivor).

The ironies continue. Gustav’s new ally at Monowitz was an ex-soldier and co-worker who simply couldn’t credit that Hitler would imprison Jews without cause. But neither could Gustav credit the number of closed trains he saw carrying thousands of Hungarian Jews to their deaths. “And all this in the 20th century,” he wrote with disbelief. A year later, starving at Mauthausen, on the outskirts of his hometown Vienna, Gustav barely escaped being massacred by ferociously antisemitic Hungarian guards. (The Russians, by contrast, treated all camp inmates with respect.)

Mauthausen was the destination towards which father and son were going when Gustav persuaded his son to leap from a speeding train of starving men and corpses, out into a snowdrift. If there are moments when Dronfield’s extraordinary book sounds more like a peculiarly gruesome thriller, readers should remind themselves that none of this is fiction. These horrors happened. Witnesses such as Gustav and Fritz survived and told their tales to ensure that their past should never be repeated. The rest is up to us.