Ultima VII Part Two: Serpent Isle - The Silver Seed

The Silver Seed expansion adds the Silver Seed story arc to the game, in which the party visits a subterranean keep in the ancient civilization of Serpent Isle (centuries in the past, during the war between the two sects of Ophidians). The Avatar is given an amulet by the Xenkan Monks when he or she first visits Monk Isle (either by death or by physically going there), and after using this amulet at one of the Serpent Gates, the subquest begins.