Investigating an archaeologist's dream. An ancient moat has been discovered and no one knows what it once protected. Was it an early Welsh chapel, a Roman fort, a fortified cattle enclosure, or even the ancestral home of one of Wales's most important families? The team visits Llancaiach Manor in southern Wales to investigate a series of strange structures found in the 1970s. What begins as a straight forward search for a missing manor house turns up a far more complex and interesting story.