In the first episode of the new series, Tony Robinson, Professor Mick Aston and the Team investigate one of Britain's greatest historic landmarks: Westminster Abbey. Surrounded by the sights and sounds of Parliament Square, the archaeologists have three days to pin down the location of a lost sacristy, a stronghold that was built by Henry III almost 800 years ago and is said to have housed the biggest collection of treasure this side of the Alps. Under the watchful eye of the Abbey's clergy and numerous tourists, the diggers' attempts to find this important building are continually thwarted by the driving London rain and centuries of later building work.