Taking place 10 years after the events of Fourth Holy Grail War and 2 months before the events of Fate/stay night, the story focuses on Lord El-Melloi II, formerly known as Waver Velvet, a successor of Kayneth and former master in the last Grail War, who is now a professor under the ranks of the Mage's Association. In his years as a professor in the Clock Tower, he is acting as the temporary head of the El-Melloi household until a proper successor can take over. When strange mysteries involving magic start occurring throughout London, he teams up with his apprentice, Gray, to solve these magical cases and expose the hidden conspiracies that drive the Mage's Association.
