Tony and the Team search for the remains of a renegade knight's Norman castle in one of Northern Ireland's most picturesque spots. King John sent John de Courcy to Ireland in 1170 as part of his invasion force, but de Courcy rebelled against his king's orders, instead establishing his own small kingdom and building a fine castle to defend it. King John refused to tolerate his disobedience and sent the loyal Hugh de Lacy across the Irish Sea to defeat him. De Courcy's castle was rebuilt, and much of its replacement is still standing. But the experts are convinced that some of what remains dates from de Courcy's time, and the archaeologists set out to find the lost structures. But as they survey and dig within the huge castle walls, they are in for a big surprise. It seems the site was occupied by tribal chiefs for many centuries before anyone had even heard of the Normans.