The hallucination wells up out of his history, leaving me depressed, scared. I’ve never had to pity him before.

My father, Hermann Henry Behrens, was born in 1910 on the Isle of Wight, England, in a house called Sans Souci, after Frederick the Great’s summer palace in Potsdam. The house belonged to my father’s godfather and namesake, Baron Hermann von Eckardstein, First Secretary at the German embassy in London, a notorious Edwardian roué, a party animal with a walrus moustache.

My grandfather, Heinrich Behrens, served in a Grenadier Guards regiment at Potsdam, then moved to England, where he managed estates belonging to German aristocrats, and married my Anglo-Irish grandmother. In England, Heinrich signed his name as ‘Henry’. His wife, from a Sligo family, always called him ‘Bobs’. Life was sunny until Great Britain declared war on the German Empire in August 1914. The Baron scampered back to Germany. Heinrich/Henry, with his British wife, and British life, and four-year-old British son – didn’t. Big mistake. In mid-August 1914 a pair of embarrassed village policeman called at Sans Souci – the name means ‘Carefree’ – to arrest Bobs as an enemy alien. He spent the next four and a half years as a prisoner, interned at Alexandra Palace, a failed exhibition hall in north London.

Hermann was not the best name for an English schoolboy during WWI, especially one with a parent in prison. My father was taunted as Hermann the Hun, and probably worse, until his Sligo grandmother started calling him ‘Billy’ after her son, Billy, who had joined the Northwest Mounted Police, and disappeared into the wilds of Canada.

At the end of the war the family were deported to Germany. Neither Billy nor his mother spoke German. ‘Billy’ wasn’t such a great name for a schoolboy in Frankfurt in 1919, but he kept it, shortened it to Bill, and taught himself the language of Goethe by reading and re-reading the Wild West stories of best-selling author Karl May. May had never been outside Germany, but his characters – Winnetou, Old Shatterhand – roamed the painted deserts of West Texas. May wrote of tribes, quests, warrior codes – matters close to the German heart, but transposed to a different key, and transferred to the Wild West. He was Hitler’s favourite author.

Bill Behrens became a tall, skinny, urbane young man who wore English clothes, belonged to a chic Frankfurt rowing club, and spoke flawless Hochdeutsch. Thanks to a Jewish friend of the family, who was a company director, he got a sales job at IG Farben, the chemicals conglomerate later notorious for using slave labour and manufacturing the poison gas used in the death camp. By 1934, with the Nazis in power, Billy was determined to leave Germany. He was posted to IG’s subsidiary in China – but when the Japanese army attacked Shanghai was sent to Montreal instead.

In the summer of 1939 he returned to Frankfurt to persuade his Catholic but hopelessly cosmopolitan parents to leave. His mother had been scolded by the local butcher for wearing English clothes. Heinrich/Henry had been admonished for declining to return a Heil Hitler greeting – but knew if he left for England, or Canada, and war broke out, he would be interned again.

The Wehrmacht invaded Poland. Billy received a warning telegram from the British consul and squeezed aboard the last train to Rotterdam hours before England declared war. Canada declared war a week later.

Back in Montreal, Billy tried joining the Royal Canadian Navy but was told he was too German.

And, now, half a century later, I’m standing by the window of his hospital room, pointing out the lights of downtown Montreal, and trying to convince him we are where we are, and that we are safe, although he is dying. Because in his mind he is back in Frankfurt once more, trying to catch that last train across the frontier.

Picking up his watch from the bedside table, I ask him to read the hour and date. His mind clears for a moment, and he laughs, and falls back on his pillow, and begs me not to tell my mother he was hallucinating. And a few minutes later he’s struggling out of bed again, determined to pack his suitcase, and rush to the damned bahnhof, and catch that last train out of here.

Photograph by Matthias Ripp