Roberts and Currie return to search for another of the Bible's lost treasures, the Holy Grail. The addition of two more individuals to the adventure rounds out a team that is extremely skilled and uniquely resourceful. Previously, in their search for the Ark of the Covenant, Roberts and Currie foiled the plans of the Ofei Cartel who attempted to secure the artifact. This new quest begins with an almost always fatal illness and the search for the healing waters of the Holy Grail, but does it even exist? Now, with an assassin on their trail, they must seek out those who know of the Holy Grail. They must acquire it and take its healing waters to a loved one who is dying. As their journey takes them from the U.S. to Wales and finally to the South of England, they encounter a number of colorful characters, spirits and changing allegiances. They must also be on their guard for a secret organization whose job it is to keep and protect the Cup. Lurking in the shadows are the Guardians of the Grail.