Donaldson told me: 'I don't suppose there'll be much peace now'
Belfast folk of both traditions have a fondness for Donegal. For many nationalists, 'Destination Donegal' is where they polish up their Irish language skills - and it is also where some of them experience the first fluttering of adolescent romance, attending Gaeltacht summer schools.
In July, the Donegal seaside village of Dunfanaghy is so popular with Protestants that local people jokingly refer to it as 'Sandy Row', after the hard-line loyalist area of inner city Belfast.
I'm lucky in that being descended of two grandparents born in the county, I got to know it well. In fact, I made it my business to become familiar with every highway, by-way, bog and boreen.
Years before I had written a hit song about Donegal, and I had helped make a documentary about the place which was broadcast on prime-time TV.
And so when an old republican contact suggested to me that Denis Donaldson - the senior Sinn Féin figure and close confidante of Gerry Adams who admitted being a British spy - may be hiding out in Donegal, I made it my business to track him down.
My source said he knew Donaldson owned an old cottage in Donegal, but the problem was, he couldn't remember exactly where it was. It wasn't much to go on, but at least it was something.
Many reporters would have given their eye-teeth in return for knowledge of Donaldson's whereabouts.
A quick word with the editor explaining my proposal, and I was on my way.
But a full day inquiring around the Gweedore region failed to turn up any clues pertaining to the elusive Denis Donaldson.
He was last seen on TV fronting-up a strained press conference, where he confessed his double-dealing. He then disappeared without trace.
The next day, I headed south to Glenties, the picturesque town made famous as Glenmornan in Patrick McGill's classic novel, 'Children of the Dead End'.
I parked outside the Bridge Bar on Main Street and I was reading a newspaper when something made me glance upwards.
I couldn't believe my eyes. Because crossing the road - not 50 yards in front of me - was Denis Donaldson, the man I had been hoping to find.
Gone was the sharp suit he wore on a daily basis while traipsing the marbled halls of Stormont as a senior Sinn Féin fixer.
Donaldson had aged considerably since I last clapped eyes on him. He had grown a scraggy beard and his wispy greying hair was in need of a trim. His cargo-pants-style trousers were tucked into boots he hadn't even bothered to lace.
The Belfast man had emerged from a general store carrying a small item in a paper bag when I spotted him. He was walking slowly in the direction of a blue family saloon car. I turned the ignition key and waited in anticipation.
Donaldson got into his car, started up the engine and drove off slowly. I followed at a safe distance.
Towards the end of Main Street, he signalled left, taking the back road to Doochary, some seven miles away.
At the top of the hill, he signalled a right and when I followed a few minutes later, I was just in time to see him walk to a small white-washed stone farmhouse.
Donaldson opened the front door and disappeared inside. I turned my car, drove back towards Glenties and waited for a journalist colleague to arrive with camera equipment.
We returned to the cottage hours later, I parked my car some 30 yards away and walked back toward the property in full view of anyone inside. We were filming the proceedings.
Before I reached the access steps, Denis Donaldson appeared at the front door which he closed behind him. I walked straight to him and introduced myself.
Donaldson shook my out-stretched hand and he told me he knew exactly who I was. As it was around lunchtime, I asked him if he fancied a bite to eat or even going for a pint in a local hostelry, but he declined both.
Donaldson had the look of a hunted animal about him and I noticed one of his eyelids flickered constantly throughout our 14-minute-long exchange.
I asked him why he took the momentous decision to turn his back on his Sinn Féin comrades, choosing to work instead for the sworn enemy, the British Secret Service.
But the former Sinn Féin man just shrugged his shoulders declining to offer any explanation.
He insisted though that there was no spy ring operating inside Parliament Buildings at Stormont.
And he somewhat bizarrely claimed he was thrown to the wolves by his British paymasters in order to save the political skin of the then Ulster Unionist Party leader, David Trimble.
Before leaving, I asked Donaldson what the future held for him.
And he pointed to the white-washed pre-famine farmhouse without running water, which had been his home for six months.
I said: "Donegal?"
He replied: "Yes, I just want to live in peace."
And then he ominously added: "I don't suppose there will be much peace now though."
A few days later, the story was published on the front page of all editions of the 'Sunday World' and it was generally accepted as a good old-fashioned tabloid scoop - Sinn Féin's Scarlet Pimpernel had been found.
All that changed though, when just over two weeks later, Denis Donaldson was shot dead in a brutal slaying inside his cottage home.
It became headline news around the world. But things had changed for me. I suddenly found myself on the receiving end of accusations that I had somehow set up Donaldson for murder.
Over the next two days, I did 67 radio, TV and press interviews. I said then and I repeated it again this week on the BBC 'Spotlight' programme which alleged Gerry Adams gave the green light for Donaldson's murder: in my view, only those who pulled the trigger or sanctioned the killing were responsible for Donaldson's death.
Donaldson was a well-known political figure in Northern Ireland. He disappeared without trace and before he had properly explained his actions.
I felt it was my duty as an investigative reporter to track him down if possible. In this regard, I was successful.
My own investigations into Donaldson revealed he was sworn into the IRA in 1964 in a Belfast alleyway alongside Gerry Adams.
It appears now, that his name will continue to haunt Adams until he decides to quit Dáil Éireann for good.