Amy Wilcock loves Beth Gadsby like a moth loves a flame. When Beth's husband Christian finds out about this, he tries to kill them both in a suicidal attempt. Beth survives but the woman she was doesn't. She disappears with her daughter Maya weeks later without so much as a goodbye. Amy tracks her down to a distant lighthouse only to find her broken and maddened in the midst of a dive into an alcoholic abyss. Now Amy must decide whether she can save the love of her life or only the traumatised child from an increasingly dangerous spiral of madness and the preternatural threat of Beth's deceased husband Christian, back from the dead and hell bent on destroying them all.