What happens when the prankster extraordinaire, James Sirius Potter (with a little help from Rose Weasley) sends himself, Albus, Rose, Lily and Scorpius back in time to 1995, Grimmauld place, breaking the most advanced time turner ever made in the process? Chaos ensues and the danger of being caught lurks ahead. How will they go back in their own time? Can James' mistake be rectified, or will they be permanently stuck in the past? Most importantly, will they even exist anymore?