This time on River Hunters at the edge of one of Britain’s greatest castles, Rick and Beau battle the forceful River Tees. In the first archaeological river search of this spot ever, the boys search for lost Tudor relics from a gruesome 16th century siege at Barnard Castle and secrets of this ancient borderland. During their search, the team unearth some potential medieval finds that could have been used in the castle at the time of the siege and also come across other finds likely to date back to the 16 and 1700s.