Nine people, from different walks of life, head to Tranquillum House, a secluded and luxurious wellness retreat where they are promised 'total mind and body transformation'. Frances Welty, best-selling romance novelist, arrives with her personal and professional life pretty much in the toilet. She is immediately intrigued by her fellow guests, apart from Tony, whom she'd prefer never to see again. The person who intrigues her most is the mysterious and charismatic director of Tranquillum House, Masha. Could this person really have the answers Frances didn't even know she was seeking? As Masha outlines the upcoming 10-day healing journey for the guests, it becomes clear that Tranquillum will not be for the faint-hearted, but perhaps this is exactly where they all need to be.

As the guests recover from Orientation, Tony brokers an arrangement with Masha. Tony and Frances clash as they both struggle to surrender to Tranquillum's restrictions, while Delilah worries about Heather's state of mind and the combustibility of this group of guests. Masha is under pressure from outside forces but remains resolute in her mission to heal the group. She will do whatever it takes to get them well.

The guests are told they must fast all day and can only forage for natural food on the property. As men and women split up to hunt and gather, the pain in Tony's past forces its way into his present, while Masha guides Napoleon to a catharsis. Jess and Carmel eventually manage to find common ground during an idyllic swim, and the men sate their hunger by taking matters into their own bare hands.

Masha comes clean about some of Tranquillum's secrets, forcing the guests to decide if they will stay or go. Heather and Napoleon disagree about the retreat's practices, and Carmel opens up to Masha in her one-on-one session. As treatment continues, Frances and Carmel let off steam that's been building for a long time. Tony reveals more of himself to Frances, and Lars's motives for coming to Tranquillum House are exposed. Pressure on Masha intensifies as Delilah remains skeptical about Masha's decision to take the protocol to the next level.

It's Zoe's 21st birthday, and the guests are all feeling the effects of Masha's stronger protocol. At breakfast, the group compares their strangely graphic dreams. Lars finds himself in an uncharacteristically vulnerable position, and Frances is caught off-guard by a dazzling blast from the past. Yao tries to help Napoleon and Heather find their way back to each other, and Jessica and Ben remember who they used to be. Zoe celebrates her birthday, surprisingly grateful for the friends she's made at Tranquillum. Masha makes a startling revelation that will allow her to take healing to the next level.

The next phase of the group's transformation tests the Marconi family, as a shocking reveal threatens to rip them apart forever. Carmel is confronted by Masha about her real motivations for coming to Tranquillum, and Tony and Frances rely on their 'buddy-system' as they become partners on their healing journey. Delilah is pushed to breaking point when Masha finally reveals why she brought the Marconis to Tranquillum.