Twilight is forced to go back to the past as a foal with Dr Whooves to save herself from being regressed into a foal forever. However, things won't be as easy for Twilight as Starlight Glimmer has some tricks up her sleeve and the two unicorns are sent through various timelines. Without Dr Whooves's time machiene Twilight now has to find alternate ways to escape these timelines to get back to the future. She can only hope nothing in her timline gets ruined.