As childhood sweethearts who had married, pursued successful careers — him as a doctor, her a senior nurse and lecturer — while raising three children, Les and Joy Milne were an enviable couple.
They had a beautiful, detached home in the Cheshire countryside in the UK, travelled widely, played squash together and were always top of the guest list on the dinner party circuit.
However, when they reached their mid-30s, Joy noticed a change in her husband — nothing to do with what he did or said, but in his body odour, the Daily Mail reports.
"He began to smell unpleasant to me and, although we always were, and continued to be, a loving couple, I was always aware of it," recalls Joy.
"It was a musky, greasy sort of odour and I would tell him he needed to shower and brush his teeth. He'd insist he was doing both of those things and I could tell that my complaining upset him, so eventually I stopped mentioning it."
It emerged many years later that Joy, now 67, was detecting in Les the early onset of Parkinson's disease, a progressive disorder of the nervous system that affects movement, mood and energy.
Because it seems she is one of a tiny band of what's known as "super-sniffers" blessed — or some would say cursed — with an ability to detect diseases simply by smell.
Almost a century ago, researchers identified changes in sebum production on the skin of Parkinson's sufferers, leading to a waxy appearance.
In the Eighties, links were made between this and the sebaceous glands in the head and neck secreting the same oily sebum, which may, researchers believe, be the cause of the unusual odour.
He began to smell unpleasant to me and, although we always were, and continued to be, a loving couple, I was always aware of it.
Although the smell lingered and Les began suffering a string of other symptoms, including tremors, fatigue, impotence, hearing difficulties and eyesight problems, he was 45 before he finally got a medical diagnosis of his condition.
"We had both concluded that the symptoms indicated a brain tumour," recalls Joy. "So, when the consultant said he believed it was Parkinson's we were surprised, though of course neither condition boded well."
There is no definitive test for the disease, which causes the neurons in the brain to break down and die resulting in a loss of dopamine, the chemical which sends signals between nerve cells, and doctors base their diagnosis on patients' symptoms.
This is tragic for sufferers who, by the time they have such obvious outward signs, also have irreversible damage to their brains and bodies.
A changed life
The Milnes, whose three sons were by then grown up, could not have foreseen that their idyllic lives would be torn apart by this disease.
Around this time Les, a gentle man who had never shown aggression towards his wife, lashed out on two occasions, once bruising her face.
Joy recalled: "The first time it happened, when we were at home, I was completely taken aback. The second time, about three weeks later, he went to lash out, I caught his arm and he backed off. As it was happening, his eyes looked blank, like he had no idea what he was doing.
"Afterwards he was utterly horrified by his actions and thankfully it never happened again. It made me sad, rather than angry, that the man I loved had done something so out of character."
Over the 20 years following his diagnosis, Joy watched her clever, athletic husband — he swam and played water polo for Scotland in his youth — become a shell of his former self.
At 50 he had no choice but to retire from medicine as hand tremors and poor concentration made his job as a consultant anaesthetist impossible.
From his mid-50s the disease left him increasingly dependent on a walking frame and it became too much effort to travel. No longer able to join in dinner party conversations, about sailing holidays or his beloved golf, the Milnes felt increasingly isolated from their social circle.
Making a vital connection
In 2005, they moved back to their native Perth, in Scotland. It was there they had started dating, aged 16, while students at Harris Academy in nearby Dundee.
Shortly after the move, while accompanying her husband to a support group for Parkinson's sufferers, Joy began to make the link between his body odour and this cruel neurodegenerative disease, which affects one in 500 people.
"After we left I said to Les: 'The people with Parkinson's in that room smelt the same as you'," she recalls. "As medical people we knew that this was significant.
"Les said: 'We have to go to the next meeting and test this again'. Sure enough, there were all different degrees of the odour, but I could detect it in every one of the Parkinson's patients."
Testing the theory
It was while listening to a talk, by Tilo Kunath, a Parkinson's and stem cell researcher at Edinburgh University, in 2010 that Joy first took the brave step of sharing her insights in public.
"Why are we not using the smell of Parkinson's to diagnose it earlier?" she asked the scientist.
Baffled by her question, and having been unaware of any smell associated with the disease, Tilo thought little more of it.
However, the following year he mentioned this apparently odd interjection to a colleague.
"She was a cancer biologist, a professor, and said that some cancers have a unique odour," recalls Tilo.
"She said that Joy might not be bonkers but actually on to something, and encouraged me to track her down, which I did."
To put Joy's super-sniffing skills to the test, in 2014 Tilo and his team asked 12 people, six of whom had been diagnosed with Parkinson's and the other half who had not, to wear a T-shirt for 24 hours. They then asked Joy to smell each T-shirt individually and say which ones gave off the telltale scent of the disease.
She correctly detected the odour, tellingly most noticeable on the collar, rather than the underarm, on six of the T-shirts, plus an additional one worn by a man in the control group.
"We were amazed at how accurate she was," says Tilo. "Eleven out of 12 seemed remarkable. Then, three months later, the same guy from the control group called me and said 'Well, you know, I've got Parkinson's'.
"Joy had told us that this guy had Parkinson's before he knew, before anyone knew, so then I really started to believe she could detect it by odour."
Promise to a dying husband
In 2015, aged 65, Les lost his battle with the condition which had robbed him of a normal middle age.
Devastated by the death of her partner of almost 50 years, Joy grieved not only his loss but for the man she had been forced to say goodbye to three decades earlier, when Parkinson's first got its grip on him.
However, she was determined to fulfil her husband's dying wish and use her extraordinary skill in detecting the scent associated with the disease in the hope that it might lead to treatments which could spare others the suffering he had endured.
Joy had told us that this guy had Parkinson's before he knew, before anyone knew, so then I really started to believe she could detect it by odour.
She says: "The day Les died he was due to have an operation on his prostate gland and, the night before that, thinking he may not survive it, I remember him saying: 'You won't let this go, will you? You promise you will do it?'"
By that stage Joy was already working with scientists who are hoping that identifying the precise molecules she can detect in the scent of Parkinson's sufferers may help lead to earlier detection, and even a cure.
Since Les's death, Joy has been able to use her keen nose to assist Professor Perdita Barran, head of mass spectrometry at the University of Manchester, in identifying 10 molecules that trigger the disease. Together they were able to isolate these molecules in skin swabs taken from sufferers.
So what is so special about Joy's olfactory abilities?
"Perdita said the strength of my sense of smell falls somewhere between a human and a dog," she says, laughing at the memory.
Tim Jacob, emeritus professor at Cardiff University and a doctor specialising in the neurophysiology of smell, says that while there are those, especially women — who have an acute sense of smell due to having more receptors on their olfactory nerves — he is "sceptical" about the existence of human "super-sniffers".
"I think the key here is that her husband's characteristic smell was so familiar to this lady, after many years together, that she was able to detect a change in it," says Dr Jacob.
"When the dopamine pathways are destroyed as a result of Parkinson's the body is no longer in its equilibrium and it results in a change in body odour. People often report detecting a change in their own scent when they are unwell."
According to Dr Jacob, that subtle but, to her, significant change in her husband's smell will have had such an impact on Joy, that it evoked an emotional response, making her sensitive to that same odour in others.
Dr Jacob's research indicates that those who report being hyper-sensitive to smells turn out to have strong emotional, rather than physical, reactions.
However, he acknowledges that certain conditions, such as schizophrenia — which creates a goat-like odour caused by the release of methyl hexenoic acid in the body — can generate a scent detectable by humans while cancer can be sniffed out by dogs.
He says: "Dogs have been shown to be 93 per cent effective in detecting prostate cancer."
Research into disease
Parkinson's was not, says Joy, the first condition she was able to identify nasally. As a student nurse she realised that she could tell which patients were suffering from gallstones before an official diagnosis was made.
"They would have raised bilirubin, the stuff that causes jaundiced skin, and I could smell it on their breath," she says.
"One time, before routine scanning, my ward sister's aunt was in for exploratory surgery, because they thought she had cancer.
"I told my boss not to worry, that it was just gallstones. She was furious with me and said, 'Don't go around saying things like that — you don't know!' When it turned out to be gallstones she apologised and asked how I knew. I said I could smell it and she looked at me as if I was crazy.
"I was only 19 and quite upset, so I told my grandma who said: 'You mustn't tell people you can do that'.
"It made me wonder if she had the same ability."
When it turned out to be gallstones she apologised and asked how I knew. I said I could smell it and she looked at me as if I was crazy.
After training as a midwife, Joy noticed she could also tell by the smell of a woman's placenta whether she smoked or had diabetes.
However, Joy's olfactory expertise has a downside: She is also hypersensitive to everyday odours and, whatever the weather, wraps a scarf around her nose and mouth to protect herself when she's out.
"I was ill in my 30s and diagnosed with multiple chemical allergies," she says. "It took five months to figure out what I needed to exclude from my diet and it turned out to be any food or wine containing sulphites, used as a preservative, plus tap water because of the chemicals in it.
"These things cause my body to swell, give me mouth ulcers and my stomach burns, as if I've drunk acid.
"I think there's a link between this and my sense of smell being so pronounced. I can't tolerate anything containing perfumes and only mineral-based make-up, otherwise my eyes swell and the skin peels off my lips."
Her ability could be considered as much of a curse as a blessing.
"I've been called the 'whiffy woman' and people will say to me: 'Ooh, don't sniff me, if I've got Parkinson's I'm not sure I want to know'.
"I have detected the odour on strangers — one time on a fellow shopper in Tesco who was complaining to a friend about feeling unwell, but, until there's a test or a cure, it's not my place to tell them.
"Once there is, however, there will be huge advantages to finding out early, before too much damage has been done to the brain to be reversed using stem cells.
"I wish that had been true for Les so we could have enjoyed our middle age and retirement together.
"Sadly, it wasn't, so now, like he asked, I'll do whatever I'm able to help future sufferers."
One thing Joy can be certain of, her husband would be very proud indeed.