When ten-year-old Arthur Blessing finds a strange antique cup, he has no idea it's the most sought after object in history. Nor does he realize the discovery of the Holy Grail will take him on a journey that defies the rules of space and time. As the cup's fate-appointed guardian, Arthur is charged with protecting it from dark magic and a madman determined to harness the Grail's legendary power. The mission threatens his very life, with assassins aligned against him at every turn. Along the way, a washed-up ex-FBI agent and a mysteriously knowledgeable old man join Arthur in his dangerous task to keep the cup safe...and unlock the secrets of the boy's own destiny.