Twenty years ago, during a particularly dry summer, parch marks revealed what seemed to be a huge Roman fort a few hundred metres from the Duke of Buccleuch's extraordinarily grand house, Drumlanrig Castle, in Dumfries. The discovery lay untouched until Time Team took on the challenge to investigate it further.

The Team sought to answer a number of questions. Was it actually a Roman fort? If so, it was one of the most northerly ever found and therefore of special importance to Scotland's history. So when were the Romans there? No finds made previously had given any hint of the date of the structure.

Time Team also wanted to identify the roads leading in and out of the fort. Was there any kind of civilian settlement or other features nearby? And could the Team work out how the Romans made their famous draco, the military standard that made a sound said to have struck fear into the hearts of their enemies?