Seven people wake up in a remote mansion. The doors are all locked. They have no idea where they are. Who brought them there. Or how to escape. Each knew the victims of a dreadful crime committed four years earlier but that's all that links them. Then a voice echoes through the house with a terrifying message. They've been poisoned - and have less than 12 hours to live. There's an antidote on hand: but only if someone admits to being a killer. And they all claim to be innocent. The time for confession is rapidly running out. How many - if any - of them will survive the night?