At around 4am that morning, my father gave an audible sigh. It was loud enough to wake my mother, who sleepily assumed that he was having a bad dream.

But he wasn’t. That sigh was his final breath as he died.

No one, least of all my father, had known he was ill. As for my mother, she’d assumed he was still asleep when she rose a few hours later and had breakfast alone.

Afterwards she’d returned to the bedroom and tried, with increasing desperation, to wake him.

There was, however, one person who knew about Dad’s death well before Mum did: my sister Katharine, who lived 100 miles away and was herself suffering from terminal breast cancer.

‘On the night of my father’s death,’ she told mourners at his memorial service some weeks later, ‘I had an extraordinary spiritual experience.

‘It was about 4.30am and I couldn’t sleep, when all of a sudden I began having this amazing experience. For the next two hours, I felt nothing but joy and healing. I felt hands on my head, and experienced vision after vision of a happy future.’

When she awoke that morning, she’d described them to her teenage son Graeme as she drove him to school. Among the visions of the future, she told him, was one of his own child — a yet-to-be-conceived five-month-old granddaughter — whom she’d played with on her bedroom floor.

It wasn’t till Katharine got back home that my mother phoned to tell her Dad had just died.

Suddenly, she knew the reason for the powerful surge of energy and joy she’d felt in her bedroom, the sense of someone there. ‘I now know that it was my father,’ she said.

Now, my family isn’t in the habit of channelling ghosts. Indeed, my first reaction to my sister’s vision was close to hysterical laughter.

But, almost immediately afterwards, the vision began to make profound sense, like puzzle pieces slipping perfectly into place. Without discussing it, we were convinced as a family that Dad had done something of great emotional elegance.

He’d seized a mysterious opportunity to go to his very sick daughter, to caress her and calm her, before heading on his way.

A month later, in early April, a scan revealed that Katharine’s cancer had spread to her bones and liver. In the final ten days of her life, in a hospice, she looked gorgeous, as if lit from within.

Sometimes, she’d have happy, whispered conversations with a person I couldn’t see. At other times, she’d stare at the ceiling as a full panoply of expressions played across her face: puzzled, amused, sceptical, surprised, becalmed — like a spectator watching a heavenly light show.

‘It’s so interesting,’ she began one morning, but she couldn’t find the words to describe what she’d seen.

She knew very well that she was dying. Forty-eight hours before she died, she announced: ‘I am leaving.’ Then a few hours before her last breath, she again mentioned leaving. How did she know? The hospice had told us that her death could be two months or six months or two years away.

Katharine slipped away in the night, in silence and candlelight, while I lay with my cheek on her chest and my hand on her heart, feeling her breathing slow and subside.

‘Welcome to our tribe,’ someone said to me wryly that summer, speaking of the crazy shift in perspective that comes with grieving. I felt as though I was gulping air, but it helped to speak to people who’d also been bereaved.

If I told them what I’d witnessed with my father and sister,  many reciprocated. And almost invariably they prefaced their remarks by saying: ‘I’ve never told anyone this, but . . . ’ Then these smart, sceptical people would talk about deathbed visions, sensed presences, near-death experiences and sudden intimations that a loved one was in danger or dying.

The director of a large music company, who drove me home from a dinner party, told me that, as a boy, he’d come down to breakfast one morning and seen his father, as always, at the kitchen table.

Then his mother broke the news that his father had died in the night. The boy briefly wondered if she’d gone mad. ‘He’s sitting right there,’ he said. It was the most baffling and unsettling moment of his life.

A casual acquaintance told me the story of her sister who’d woken one night to the sensation of glass shattering all over her bed, as if the bedroom window had been blown inward. With adrenaline rushing, the sister leaped out of bed and felt around gingerly for the shards of glass.

There was nothing there; the window was intact. The next day, she learned her daughter had been in a car accident, in which the windshield had shattered.

Were these people, and many others I spoke to, suffering from overactive imaginations? Hallucinations? Wishful thinking? I decided to investigate.

In the late Nineties, I discovered, Michael Barbato, a palliative care doctor, had designed a questionnaire specifically for the families of patients who witnessed uncanny events. To his surprise, 49 per cent reported they’d had a strange experience.

‘Even if we cannot understand the basis for these phenomena,’ Barbato argued, ‘the weight of evidence suggests we cannot continue to ignore them.’

Certainly, you cannot ignore them when they happen to you.

Why had my sister had a powerful spiritual experience in the hour of my father’s unexpected death? How did she sense a presence in her bedroom, and feel hands cupping her head?  Why did she become increasingly joyful as death approached?

What I discovered was far richer and more mysterious than I’d ever imagined.

DEATH AS A JOURNEY

Within roughly 72 hours of the end of their lives, many dying people begin to speak in metaphors about a journey.

Often, they haven’t said a word in days — then suddenly they want to know where their train tickets are, or ask for hiking shoes or tide charts. Some demand their coats; others inquire about the bus schedule.

To families, these febrile mutterings can seem of no importance. Far more significant to them, perhaps, would be the whispered ‘I love you’ or ‘Take care of the children’ before the head falls back on to the pillow.

But hospice staff know that when their patients begin to talk about excursions or travel, they’re in fact announcing their  own departure.

David Kessler, former chair of the Hospital Association of Southern California Palliative Care Transitions Committee, has observed this phenomenon many times. It even has a name: Nearing Death Awareness.

‘Interestingly enough,’ he says, ‘it’s always referred to as an earthly journey. People talk about packing their bags or looking for their tickets — they don’t mention chariots descending from heaven or travelling to eternity.’

Kessler recalled a 96-year-old man who suddenly woke up in his hospice bed and told his daughter: ‘Gail, it’s time to go. Let’s make a run for it. I have to be free — is the car ready?’ When she assured him that it was right outside the hospice, he said: ‘Good. I’m ready.’

She asked him where they were going, and he said he wasn’t sure. ‘I only know that I’ve got this trip in front of me, and the time has come.’ He died shortly afterwards.

There is no known medical reason for the dying to have such an acute sense of timing about their demise. When patients talk about going on a trip, they rarely look as if they’re about to expire — or, indeed, show any marked deterioration in blood pressure or oxygen levels.

‘I’m going away tonight,’ the soul singer James Brown told his manager on Christmas Day 2006, after being admitted to hospital for pneumonia that wasn’t thought to be life-threatening. Immediately, his breathing began to slow.

In the most comprehensive study of deathbed experiences ever done, psychologists Karlis Osis and Erlendur Haraldsson confirmed that these intimations of departure do sometimes come to people who aren’t considered to be in danger.

Among the cases they examined was that of a man in his 50s, about to be discharged from hospital on the seventh day after a hip operation.

The patient called a doctor over and told him he was going to die. A few seconds before, the patient said, he’d sensed he was not in this world but elsewhere. ‘I am going,’ he told the doctor, and he died a few minutes later.

Meanwhile, hospice staff report that patients can sometimes predict the precise hour of their departure. Yet, to date, no one has come close to finding a scientific explanation.

VISIONS ON THE DEATHBED

Despite the concerned obstetrician by her bedside, Doris was unmistakably dying. Her baby had been born safely, but there’d been rare and unforeseen complications.

It was what happened next that stunned the obstetrician, Lady Florence Barrett, and later caused  a sensation.

‘Suddenly,’ Lady Barrett recalled, ‘she looked eagerly towards one part of the room, a radiant smile illuminating her whole countenance. “Oh, lovely, lovely,” she said.

I asked: “What is lovely?”

‘“What I see,” she replied in low, intense tones. “Lovely brightness  — wonderful beings.”

‘Then — seeming to focus her attention more intently on one place for a moment — she exclaimed: “Why, it’s my father! Oh, he’s so glad I’m coming, he is so glad.”’

Briefly, Doris reflected that she should, perhaps, stay for the baby’s sake. But then she said: ‘I can’t — I can’t stay; if you could see what I do, you would know I can’t stay.’

At this point, Doris saw something that confused her: ‘[Father] has Vida with him,’ she told Lady Barrett, referring to her sister, whose death three weeks earlier had been kept from her because of her advanced pregnancy. ‘Vida is with him,’ she said wonderingly.

Afterwards, Lady Barrett told Doris’s story to her husband Sir William, a physicist at the Royal College of Science in Dublin. He decided to launch a formal investigation.

Among the evidence he gathered were recollections of Doris’s vision from his wife, an attendant nurse, the resident medical officer, the matron and Doris’s mother — all of whom had been in the room.

His published account in 1926 became the first modern, corroborated report of a deathbed vision. Since then, however, there have been literally thousands more.

In one study, by University of Virginia psychologist Emily Williams Kelly, 41 per cent of the dying patients surveyed had reported a deathbed vision.

Another study, which questioned staff in five hospices, revealed 54 per cent of them had tended to patients who’d experienced a ‘visit’ from a dead relative — and this was always very close to the time of death.

And in their huge study of deathbed experiences, psychologists Karlis Osis and Erlendur Haraldsson reported that of the 10 per cent of patients who were conscious in the hour before death, the majority said they’d had these visions.

Eighty-three percent were of either dead people or religious archetypes — such as angels.

‘Such experiences can happen to patients who are convinced they will recover and who are not at all ready to go,’ the researchers discovered.

‘A cardiac patient, a 56-year-old male whose consciousness was clear, saw the apparition of a woman who’d come to take him away.

‘He did not seem to be repulsed by her, just slightly frightened. He said: “There she is again, she is reaching for me.” He did not particularly want to go, but he did not make a fuss. He became calmer; this experience made him serene. He died a day later.’

Are all such patients hallucinating? Probably not: the psychologists found that only 10  per cent who had visions also had high fevers, which can trigger hallucinations.

Were these patients’ brains impaired by disease or the drugs they were taking? Again, this seemed unlikely.

The more confused or medicated patients were, the less likely they were to perceive  a consoling or beckoning presence.

Informally, nurses often use these visions as a gauge for impending demise. What is also remarkable is that — in contrast with those who are agitated as death approaches — the patients who have visions experience a profound sense of calm.

As one nurse in a UK hospice study said: ‘It’s like a process and once they’ve experienced it, they move on to a different level. It’s like a journey.’

In nearly 80 per cent of Osis and Haraldsson’s cases, the apparent purpose of the deathbed vision was to accompany the patient or take them away.

In fact, they didn’t find a single instance of an apparition with this purpose who turned out to be someone was still alive.

The two psychologists also examined what they called ‘the mirage effect’.

Could these visits from sisters and uncles and angels be like the wishful thinking of a man in the desert who conjures up a shimmering pool of water?

A couple of factors made that an unlikely explanation. First, patients in distressed or anxious states were less likely to see apparitions than those in calmer moods. Second, some patients who had the visions hadn’t been expecting to die.

One summer afternoon, I went with a friend to interview a dying patient. Audrey Scott — 83 and in the final stages of cancer — was lying on a borrowed hospital bed in the middle of her living room.

We clasped hands, and regarded each other frankly. Dying has a tendency to dissolve all pretension.

‘What do you want people to know about dying, Audrey?’ I asked.

‘There should be no fear,’ she said without hesitation. ‘Life is laid out from birth to death; it’s all just part of the process.’ I asked if she was experiencing anything unusual. She studied me, a note of caution in her expression.

‘I see things twirling in the room,’ she said. ‘It’s quite pleasant, actually.’ After a pause, she added: ‘My son Frankie has been visiting me. He sits there.’ She gestured toward an armchair to my left.

Our mutual friend, Judy, who’d been standing discreetly near the window, reached up to the window ledge behind Audrey’s head and picked up a photo of a smiling young man with thick, square glasses.

This was Frankie, who had died of cancer in 2002 at the age of 35. I angled the frame toward Audrey, but she evinced no interest.

She didn’t need to have a nostalgic look at a photograph — not when the real Frankie was sitting right here in an armchair. As we continued to chat, I had a curious sensation that my body was vibrating. It had the thrumming feel of an impersonal energy, rather than a rush of nerves — and I didn’t know what to make of it.

Later, a friend who’d been volunteering in hospices described a weird sense of surrounding energy, which had almost caused him to pass out.

So did my sister’s best friend, who had been massaging Katharine’s temples when she suddenly realised she was about to faint.

Maybe it has to do with the life force receding — like being too close to a whirlpool or a riptide.

Audrey died, at her home, ten days later.

THE LUCID LAST WORDS

Only recently have scientists begun to take note of a phenomenon first observed by doctors in 19th-century insane asylums in France, Germany and the U.S. Back then, they called it terminal lucidity.

Patients with severe and chronic mental illness or dementia would suddenly start speaking clearly and rationally before death.

Even those with amnesia often recognised family members for the first time in years, and were able to say goodbye.

More recently, nurses and physicians have been noticing this phenomenon as more people end their lives in hospices.

In 2007, Dr Scott Haig wrote an account of his patient, David, who had lung cancer that had spread to the brain.

First, David’s speech had become slurred and then he’d  lost the ability to speak or  even move.

A brain scan done by his oncologist showed that there was scarcely any brain left.

For days, said Haig, his patient had ‘no expression, no response to anything we did to him’.

Then, when the doctor made his evening rounds one Friday, he noticed that David had lapsed into the laboured breathing that often presages death.

But an hour before he died, he woke up, and talked calmly and coherently to his wife and three children, smiling and patting  their hands.

As Haig noted: ‘It wasn’t David’s brain that woke him up to say goodbye that Friday.

‘His brain had already been destroyed.’

Psychiatrist Russell Noyes had  a similar case: a 91-year-old woman who’d lost her capacity for speech and movement as a result of two strokes.

Yet she suddenly broke through those walls shortly before  her death.

Smiling excitedly, the woman turned her head, sat up without effort, raised her arms, and  called out happily to her dead husband. Then she lay back down and died.

Whether or not she’d had a vision of her husband, the far more difficult and astonishing fact was that she’d regained her speech and mobility.

• Adapted by Corinna Honan from Opening Heaven’s Door by Patricia Pearson, published by Simon and Schuster. © Patricia Pearson 2014
• This article was originally published on May 17, 2014