I first learned of my father's plane crash from the Jerusalem Post. I was 22 and working as a journalist in the Middle East, half a world away from my home in Canada. The crash occurred on 19 October, 1984, but I didn't find out about it until two days later while reading the morning paper. That day it wasn't regional conflict or politics that caught my eye, but the headline of a short news item buried at the bottom of an inside page: Party Leader Killed in Alberta Plane Crash.

The article was tiny – fewer than 50 words – but its impact was staggering. "Grant Notley, the leader of the New Democratic Party in Alberta and five other people were killed in the crash of their twin-engine plane," the Associated Press reported in the opening line. I read on in disbelief. Four survivors had spent the night and much of the next day huddled in deep snow and sub-zero temperatures before being rescued. Among them was Larry Shaben, a provincial cabinet minister: my father.

I dropped the paper, and grabbed the phone.

"He's OK," my mother told me. "We were going to call, but it's been crazy and, well … we didn't want to worry you."

I was sobbing, feeling very far away. "I'm coming home," I said.

It was Christmas before I could get time off work to return to Canada. Two months had passed and my father's physical wounds had healed. Inside, however, something elemental had changed. He was subdued; quietly haunted in a way I had never seen before. He'd lost a close colleague that night and had seen others from our town and the surrounding communities die. My family had experienced the event firsthand and assimilated its extraordinary details. The survivors of the crash – a rookie pilot, a criminal, a policeman taking him to face charges, and my father, a prominent politician – had boarded the plane as total strangers. Men from wildly different backgrounds had helped one another survive a long, bitter night in the Canadian wilderness. The story had a mythical quality that tested the bounds of reality.

Though I peppered my father with questions, his answers were disappointingly vague or simply not forthcoming. He refused to discuss the people who had died or what he had shared with the men who survived. My mother too, was closemouthed about the details of my father's ordeal, though I was never entirely certain how much of this he had revealed to her. "He has nightmares," was all she would say.

Though I desperately wanted to know what my father had endured that long night during which he and his fellow survivors had cheated death, I knew better than to push. A second-generation Canadian of Lebanese descent, my father was the undisputed patriarch of our family, demanding utter respect and not given to sharing his doubts or demons with his children. Though wildly curious, I accepted that there were questions I couldn't ask, and moved on.

At first it seemed that my father did too. He returned to the sombre atmosphere of the legislature and threw himself back into political life. But in the months and years that followed, it became clear that my father had forged extraordinary bonds with his fellow-survivors, especially Paul Archambault, the 27-year-old on the plane who was being transported to face charges. The night of the crash, Paul had boarded the plane in handcuffs. Against regulations, the young Royal Canadian Mounted Police constable escorting him had removed Paul's handcuffs. As fate would have it, Paul was the only person to escape the crash uninjured. It was Paul who pulled his RCMP escort from beneath the fuselage where he was buried, and who stoked the fire that kept my father and the other survivors from freezing to death that night.

After the survivors were rescued, the authorities took Paul into custody; he would appear in court 48 hours later. A day before that appearance, my father spoke to the media from his hospital bed. One reporter congratulated him, suggesting he'd been heroic.

"No," my father corrected him. "Paul Archambault is the hero."

By the time Paul had his day in court, the judge had heard my father's testament: the accused, a man with a lengthy rap sheet and a four-year prison record, had saved the lives of his fellow passengers. The judge commended Archambault for his actions and exonerated him of all charges.

From time to time, the young drifter would arrive unannounced at my father's office at the Alberta legislature. No matter how busy my father's schedule, he always had time for him. My dad would recount these meetings with delight and obvious affection. Their relationship was important to him in a way I never fully understood. He cared deeply about how Paul's life was progressing and worried during his long absences as a father would for an itinerant son. After one visit, my dad spoke enthusiastically about a dog-eared sheaf of papers that Paul had brought with him, a manuscript he was writing about his experience that night. It was titled: They Called Me a Hero.

I was captivated; brimming once again with questions I never had the opportunity or courage to ask. Sadly, the upward trajectory of Paul's life did not last. Within five years he had disappeared from my father's life and when news reached my father that Paul was found dead along a lonely stretch of train tracks, he was devastated.

The previous year, at the apex of his political career, my father had abruptly decided to leave politics. He seemed unsettled, searching for something unattainable, and – for the first time I could remember – unsure of his direction in life. Meanwhile, my life marched on. I moved away, married, launched into a career in another city and started a family. Over the next decade, I had little time to dwell on my father's life.

In the brief times we were together, I was often moved by his desire to impart a profound nugget of wisdom or by the way he hugged me as if he would never let go. I continued to question whether the crash had had an impact on his life. Had it changed him? If I had faced a similar near-death experience would it change me? Would I continue to live my life as I had been living it? At the same time, I accepted that there were parts of my father, aspects of his life, I would never know.

Then, 20 years to the day after the plane crash, my father announced that he was organising a reunion of the remaining survivors. He was approaching 70 and Paul Archambault had long gone from his life, but he felt compelled to reunite with the former rookie pilot and RCMP officer.

"It felt like something that had to be done," he told me.

It was after that event that my father confided in me that he measured his worth as a man by what he'd contributed to society during the extra years God had granted him and not others.

Three years after the reunion, my father was diagnosed with cancer. He died less than five months later. By then I had started writing a book about his plane crash and the impact it had had on not just my father, but all of the men who had survived – perhaps to address unanswered questions before the opportunity was lost for ever.

As I was preparing to board a flight to be at my father's bedside, I asked him if there was anything he wanted me to bring.

"Your manuscript," he said.

I'd written only a few rough chapters, but it didn't matter. He insisted.

I spent two days at the hospital. And during those two days I read to him. It was the last time we were together.

It wasn't until after my dad died that I began in earnest to search for information about Paul Archambault, the man credited with saving my father's life. Thinking it a long shot, I placed advertisements in newspapers on either side of the country – one in the city where Paul was living at the time of the crash and the other in the town where he'd grown up 3,800km away.

To my amazement, my phone started ringing almost immediately. Those who called not only remembered Paul, they said he had made a lasting impression. Though his parents were dead, an aunt in his hometown of Aylmer, Quebec, contacted me. They were in occasional touch with his younger brother who had been institutionalised for mental illness in his early life. They didn't know the brother's whereabouts, but told me that he called from time to time. "When he does, could you give him my number?" I asked without hope.

Months later, Paul's brother called. Miraculously, in his possession was Paul's tattered 60-page manuscript that my father had spoken of a quarter of a century earlier.

I clearly remember the spring day in 2011 when the manuscript arrived. I stood in my living room holding a 25-year-old document I thought had long been lost to history. Then I sat down and began to read. As I did, I began to truly understand my father.

There is a passage in Paul's manuscript where he describes a moment when – after the survivors had endured hours in the freezing wilderness and despaired that they would freeze to death before rescuers could find them – he began to shiver violently. My father came up to Paul, put his arms around him and held him until he stopped shivering. Reading that made me cry because I realised that my dad had hugged me in exactly the same way so many times during my life when I needed comfort.

My father had been gone two and a half years when I read that passage, but the brief window it provided into his character – illuminated through the eyes of a luckless drifter – spoke volumes to me about the kind of man my father was: a man who quietly carried within him an unwavering compassion for others; a man who didn't distinguish between rich and poor, black and white, Christian, Muslim or Jew. It also imbued in me a lasting and unshakable hope that no matter who we are or what befalls us, we all have the capacity to overcome tragedy, reach across the divide to others and transform our lives.

• Into the Abyss: A True Story, by Carol Shaben, is published by Macmillan, £16.99. To order a copy for £13.59, including free UK p&p, go to theguardian.com/bookshop or call 0330 333 6846