Following the deaths of her last living relatives, Hetty Deveraux returns to her ancestral home, a crumbling estate in Scotland's Outer Hebrides, with the intention of renovating and reselling it as a hotel. As she dives headfirst into the repairs, she discovers human remains beneath a rotting floorboard in the basement. Hungry for answers, Hetty sets out to unravel the estate's secret-and those of its former inhabitants, including Beatrice Blake, a woman who moved there a century ago with her husband Theo, a famous painter. Following whispered rumors and a handful of leads, Hetty soon discovers that no one knows exactly what happened to Beatrice, only that her actions have reverberated throughout history, affecting Hetty's present in startling ways.