A group of strangers arrive on a beautiful but remote island, ready for the challenge of a lifetime: to live there for one year, without contact with the outside world. But 12 months later, on the day when the boat is due to return for them, no one arrives. Eight people stepped foot on the island. How many will make it off alive?

Stacey and Felix are the glamorous owners of the stylish, modern Glass House, with its pool and floor-to-ceiling windows. Now they’re downsizing, but Stacey can’t sell to just anyone. She needs the right buyer, who will keep her secrets. Millie and Tom have always imagined living in the Glass House. Now it’s for sale. With property prices booming, if they can sell quickly, it could be theirs. But is the house and its charming owners all they seem? Harper and Kyle are moving up in the world.

Thirty-eight year old Cassandra is lost, alone, and grieving. Her much loved grandmother, Nell, has just died and Cassandra, her life already shaken by a tragic accident 10 years ago, feels like she has lost everything known and dear to her.

Kirsten and Nick are enjoying a weekend away until, on their drive home, they accidentally run over and kill a man. They should call for help – but they have too much to lose, and no one can know the real reason they’re here. Instead, they make a split-second decision to conceal the accident. Amy and Greg have just celebrated their tenth wedding anniversary. Amy is expecting a baby, and they couldn’t be happier. So when Greg fails to come home from a dog walk one weekend, Amy knows the police are wrong to believe he left of his own accord.

Your daughter isn't answering your calls. She's not replying to your messages. You rush to her house. She's slumped in the basement, dying and alone. You desperately call for help. She whispers a single word. Someone is keeping secrets. And it must be someone you know.