Margate is in the grip of a heatwave when David Whitehouse stumbles across the mysterious story of a local woman who lived on the ground floor of Saltwater Mansions, a block of flats not far from the sea. But nobody had seen or heard from her for 13 years, and no one had ever come looking. She had disappeared completely. David quickly becomes as fascinated by this missing woman as the residents of Saltwater Mansions, all of whom have their own theories to share, and their own unique stories to tell.