Mika Castell (or MC for short) is now a seventh-year student at Hogwarts School of Witchcraft and Wizardry after conquering all six of the cursed vaults. They can finally rest and take it easy, or can they? Everything changes for the worse when their former mentor turned traitor, Rakepick, kidnaps them and uses them as blackmail for the key to what could be the deadliest vault of them all.