When the residents of St Kilda ask to be evacuated from their remote island home in the summer of 1930, it's in search of a better life on the mainland rather than the scratch existence on their mountain in the sea. For 18-year-old Effie Gillies, it's a bittersweet departure. She's the best young climber on the island, as skilled and brave as any of the men. But it is Effie's expansive knowledge of local bird life that leads her to taking up a position as curator of Dumfries House's ornithological collection - and back into the arms of Lord Dumfries' son and heir, Sholto. During her last summer on St Kilda, Effie had been Sholto's guide, and their attraction had seemed irresistible. But in the glamorous polite society of Ayrshire, it is clear they are worlds apart. When a body is discovered on the island, soon after the evacuation, a scandal erupts as she is implicated. Sholto knows she's keeping secrets - but are they even her own?