Harriet has a complicated life. She cares for her chronically ill Mum, while trying to juggle school and a social life. She's tired, overworked and underpaid.Yet, one day she sees what she thinks is a ghost, but ghosts don't exist do they? And they especially don't help you travel in time, right?Now Harriet has a murder to solve, all the while trying to make sure no one finds out about the secret behind that stone in her back garden.