Are the bones of a historic Irish leader entombed below the foundations of a bank in northern Spain?
Archaeologists have dug up a street in the city of Valladolid in a bid to find the remains of a 16th Century Irish chieftain known as Red Hugh.
Red Hugh O'Donnell died in Spain in 1602 while on a mission to ask the Spanish king for military assistance to drive the English army out of Ireland.
He was buried in Valladolid's Chapel of Wonders - the same church where Christopher Columbus was interred almost a century earlier.
The remains of Columbus were later moved to Seville and the ruined building eventually disappeared from view.
However, archaeologists believe they have unearthed the walls of the chapel and are "close" to discovering the remains of Red Hugh.
The dig in Calle Constitución (Constitution Street) began earlier this month, outside a branch of the Spanish bank, Santander.
Two coffins and 15 sets of unidentified human remains have been found so far.
The team is "very excited" about their discoveries, according to Carlos Burgos, spokesman for the excavation project.
"It's very important to the history of Spain, and of course our city," he told BBC News NI.
Mr Burgos is also president of the Hispano-Irish Association and said the story of Red Hugh was part of the "common history" shared by Spain and Ireland.
The cause of O'Donnell's death is still disputed, so finding his remains may help either confirm or dismiss claims that he was killed by poison.
His skeleton should also be missing a big toe from each foot - injuries a young Red Hugh suffered while escaping from his English captors.
The team does not yet know which, if any, of the skeletons recovered so far is that of Red Hugh, but at least two can be ruled out because they were women.
The others could be the remains of monks, Mr Burgos suggested, as the chapel once formed part of a large Franciscan monastery.
Red Hugh is more likely to have been buried in another part of the chapel - a crypt which may be located underneath the bank, according to the dig's spokesman.
On Friday, the team secured permission to excavate within the grounds of the bank but the work proved extremely challenging and had to be paused.
Red Hugh O'Donnell was chieftain of the O'Donnell clan, a powerful dynasty based in what is now County Donegal in north west Ireland.
He helped to score a number of significant victories over the forces of Queen Elizabeth I, forming alliances with other clans to pose a serious challenge to English power in Ireland.
He is often a romanticised figure and his exploits even inspired a 1960s Disney movie - The Fighting Prince of Donegal.
As a boy of 15, Red Hugh was kidnapped and held hostage in Dublin Castle to discourage his family from rebelling against the crown.
He escaped five years later with the help of another Irish chieftain, Hugh O'Neill, his future father-in-law.
But as he fled home across the mountains in winter, Red Hugh suffered severe frostbite and lost a big toe from each foot.
The O'Donnell and O'Neill clans were rivals, but they joined forces against the English in a series of battles known as the Nine Years War.
In 1601, they persuaded Spain's Catholic King Phillip III to send thousands of troops to Ireland to help fight their common enemy - the Protestant Elizabeth I.
But when Spanish ships arrived in County Cork, English troops surrounded the port of Kinsale and hundreds of Spaniards died in the siege.
After suffering a heavy defeat at the Battle of Kinsale, Red Hugh travelled to Spain to ask the king to send more soldiers.
O'Donnell died before his plea was answered - some accounts say he was poisoned by an English spy while others say he succumbed to infection.
His body was taken to the king's palace in Valladolid, once the capital of Spain, where palace guards and state officials attended his funeral.
The search for Red Hugh was sparked more than a year ago by a retired Irish soldier from Donegal.
During a visit to Valladolid, he asked the city's authorities if they knew the location of the grave.
The Mayor of Valladolid, Oscar Puente, has embraced the project with enthusiasm, visiting the excavation site and updating his Twitter followers on the dig's progress.
So what are the chances of finding an eight-toed Irish skeleton underneath a branch of Santander?
Don't bank on it just yet - Mr Burgos said only one of the 15 skeletons' feet remained intact when discovered.
Expensive DNA testing will be required to identify the remains and the team is seeking support from both the Irish and Spanish governments for the project.
But the biggest problem is still locating the crypt, because searching underneath a four-storey building has proved much more challenging than digging up a street.
"It's really difficult considering there is a building on the chapel," Mr Burgos said.
But he is not giving up hope, adding: "We will try to see if there is any possibility of going inside the chapel by other sides."
For now though, he says the team will concentrate on a new phase of the project - "the study and analysis of the remains of the 15 bodies which have appeared".