“Charlotte and Mia are delighted to meet the mermaids who live in the lagoon in the grounds of Wishing Star Palace. But in the middle of all the fun, the lagoon suddenly turns a murky, toxic green. Nasty Princess Poison is up to her old tricks again! Charlotte and Mia have to grant four more wishes to break the evil curse.Freya wishes to find the buried treasure on her family’s treature hunt. Can Charlotte and Mia grant Freya’s wish and solve the mermaid mystery?”