Blown through time by a rogue curse at the bloody climax of the Battle of Hogwarts, a battle-scarred student crashes into a vibrant, untouched 1970s Great Hall and stands face-to-face with the dead heroes of the Marauders era. Surrounded by happy, living ghosts who have no idea a war is coming, they must decide whether to find a way back to their own desperate timeline, or stay and use their dark future knowledge to rewrite history from the roots up.