When military historian Dan Snow and a team of archaeologists unearthed a Second World War Spitfire from an Inishowen bog in County Donegal, it kicked off a remarkable, and often surprising, documentary journey.
We would film six Browning machine guns emerging from the muck that day, followed by a fully inflated tail wheel and the preserved leather flying helmet thrown off 70 years earlier by American pilot Bud Wolfe.
Despite everything that came out of the ground, what seemed most striking was how far the fighter plane was from, what I presumed, was the heart of the battle, in Europe.
But this was where we began unearthing a unique story: how Northern Ireland played not a small part, but a pivotal role in the war.
The fact that this role often goes unnoticed is unfortunate. But, while it's often forgotten about, it made for some extremely fruitful digging.
The Donegal Spitfire made world headlines, but it was only the beginning. With over 350 Second World War sites in Northern Ireland, there were plenty of artefacts yet to surface.
Just north of where Bud Wolfe had bailed out, we found another extraordinary wreck, this time buried in 228 feet of water. The Empire Heritage was torpedoed by a German U-boat in 1944, sinking in mere minutes.
We picked up its story on the seabed, where divers filmed the carnage nearly seven decades later.
Still, it became obvious from the footage that this was an important ship, her cargo bound for the frontlines - dozens of American Sherman tanks litter the seabed around the wreck to this day, tanks that would never see a fight.
The Empire Heritage was a casualty of the Battle of the Atlantic, the longest continuous battle in the Second World War. It was fought on our doorstep. And it was won from the ports and airfields within our borders.
The more we dug, the more Northern Ireland's important contribution surfaced.
And of course there was sacrifice and the reminders of wartime perils: a B-17 forced to ditch in Lough Foyle, soldiers that didn't make it home, or the haunting remnants of German U-boats, whose wrecks lie just off our coast.
But the most poignant reminder of all for me was on a small island in Lough Neagh.
Ram's Island still bears witness to the American soldiers that came here in the run-up to D-Day. Carved into the beech trees are the names of some of these soldiers, a memorial left by them in the days before leaving to fight.
These names, yet another reminder of the part Northern Ireland played, a part sometimes lost in history, but now, with a little digging, not forgotten.
The three-part series, Dig WW2 With Dan Snow, starts on Monday, May 14 at 9pm on BBC One Northern Ireland.