When Sir Galahad arrives in Camelot, his vision of the Holy Grail at Pentecost inspires the entire fellowship of the round table to rush off in quest of the most holy relic. But when knight after knight turns up dead or seriously injured, Gildas and Merlin begin to suspect some sinister force behind the grail madness, bent on nothing less than the destruction of Arthur’s table. They begin their own quest: to find the conspirators behind the deaths of Arthur’s good knights.