Running from charges of professional misconduct caused by her fentanyl addiction, Mia answers her estranged sister Cassy's invitation to her wedding and flees to New Zealand’s ominous mountains. But when Cassy’s body is found in a crevasse and doubt starts to creep in on the circumstances of her death, Mia must dive into her sister’s intimacy to discover what really happened on the mountain ridge.
For Mia, that means unraveling the puzzle of her own troubled past and facing her inner demons. While a mysterious presence looms over the mountains, she finds comfort in Cassy's fiancé Ewan and soon develops a forbidden attraction towards him. As she’s drawn into the community’s raging war between environmentalists and farmers, Mia soon learns about Cassy’s involvement in the town’s turmoil and the extreme lengths her and Ewan were willing to go to. Can Mia trust him and those around her to discover what happened to her sister? But most importantly, can she trust herself?