The children of Mivtown have grown up hearing the legend of the monsters of the loch. But it's only a story - a warning to stay away from the water.
Then strange things start happening in the village. Effie's rabbit Buster escapes from a locked hutch, her mum disappears without trace and slugs start to infest her home.
Along with her best friend Finn, Effie begins to hunt for clues to solve the mysteries of Mivtown. Could this all be connected to the legend? Is it really just a story or is there something lurking in those deep, dark waters?