Esmie has always longed for a new mum, since her real mother died when she was a baby. So when Lizzie moves in, Esmie is delighted. Surely it can only be a matter of time before Dad proposes and Lizzie becomes an official mum. So why does Matty, Esmie's brother, suddenly have cold feet about the whole thing? But Esmie has even more pressing problems: like the discovery of her mother's old jewellery box that leads to a mystery about her past. And then there's Esmie's friendship with a new girl in the street who claims to have psychic powers. Esmie has always loved mysteries – but never before have her detective skills been so thoroughly put to the test!