A stomach bug sweeps through Portwenn. Martin creates mass panic by declaring it's the swimming pool, and then infuriates the locals by blaming the village water supply. Meanwhile, plumber Bert Large is making a mint off his new business: bottled water.
It’s Martin and Louisa’s wedding day. The bridesmaid is injured, the vicar is drunk, the reception hall floods, and Martin encounters a pig. Things go downhill from there.
The team is helping the Camelot Society try to find King Arthur's grave despite the reluctance of some of the locals. A mysterious accident and the appearance of the Dark Rider, a ghostly rider said to attack thieves and vandals, plague their efforts. Gabe suspects the son of the local Lord Richard Briarcliff, Morgan, and evidence is planted on Morgan to make him look guilty. Judson finds the apparent remains of Arthur.
