It's like the plot from some Dan Brown thriller – imagine the existence of a huge ecclesiastic manor of great importance that has somehow, mysteriously, disappeared from history.
No obvious mention has been made of the giant pile in any archive for over 600 years – and added to that remarkable fact, almost all the materials that once formed the large buildings have also vanished without trace...
Not even the painstaking searches of archaeologists can show where the doors, windows, rafters, mullions, roof slates, floor tiles and all the rest of the materials you'd expect in a large manor house have gone.
Experts only know it existed at all because they've uncovered the massive foundations of an ancient mansion just outside Wellington – along with one or two crucial bits and pieces of historic evidence that prove that this really was once a place of great importance.
So did its denizens do something breathtakingly terrible when they occupied the manor at Longforth Farm between the 12th and 14th centuries? Were they wiped out by some terrible plague or murdered in their beds? Was their religious sect banished from the history books?
It remains a true riddle of the Somerset sands and archaeologists have a lot more questions than answers. But what they did reveal at a special opening of the dig next to the Westcountry's main railway line yesterday were some items that prove the mysterious manor was a place a great importance.
The shards of mediaeval decorated floor-tiles indicate that the place was once occupied by someone rich and powerful – moreover, another tile illustrated with a knight on horseback has added to the belief that the Longforth manor was a place visited by bishops and other VIPs of the day. The only other tile ever found like it is a well-known feature of Glastonbury Abbey.
"These are our latest finds and the decorated floor-tiles have given us an avenue to pursue – they have raised the importance of this place for us," commented Bob Davis, the expert in charge of the dig for consultants Wessex Archaeology, who were brought in to survey the site by development company Bloor Homes, which is about to build 500 houses nearby.
"We are familiar with ordinary decorative floor-tiles, but these are special – they have taken the importance of this building up a peg or two," he added, saying this was the most exciting mediaeval dig he'd been involved with in 26 years of archaeological work.
"Preliminary dating of pottery sherds suggest that the buildings were occupied between the 12th and 14th centuries. At some stage however, the buildings were abandoned, the useable building materials were robbed out and recycled and the site was forgotten."
Steve Membery, senior historic environment officer for Somerset County Council, said: "It is very unusual, normally you have the historic references – we know where all the mediaeval villages are – manor houses are well recorded.
"This is one of the most unusual things to have happened archaeologically in the Westcountry for a long time," he went on. "This sort of thing turning up – a large mediaeval building of such high status without any surviving historical records – it is exceptionally mysterious and strange."
Mr Davis added: "It looks as if it is a previously unrecorded, undocumented, high-status, ecclesiastical manor house. Such things are as rare as hen's teeth.
"Hopefully, this fills in a missing bit of the jigsaw of medieval Somerset," he said, adding that his team will be asking the local community to become involved. "Local history societies and so on are fantastic at finding evidence in the archives and we'll be encouraging them to do some detective work."
The dig will finish in three weeks, after which this low-lying corner of the giant development site will be formed into a pond designed to cope with water run-off from the new housing estates. This should protect the ancient remains for centuries to come.
Paul Talbot, of Bloor Homes, commented: "We are delighted to have been able to fund this excavation which has enabled Wessex Archaeology to examine and record this exciting find and to help the community understand more about Wellington's hidden heritage."
But who knows exactly what that heritage is? Or, for that matter, where it went?
As one archaeologist said yesterday: "Who knows – half the old buildings in Wellington could have 'borrowed' materials from this manor incorporated in their walls."