Helena and her twin sister Siri have long lived separate lives. As a reunion approaches, Helena says yes and travels to an idyllic resort in the Italian Alps, but it quickly turns out that Siri has her own agenda with her invitation.

Doctors disagree on how to interpret "Siri's" sudden behavioral improvement. Helena realizes that she can take advantage of her fellow prisoners' fear of Siri and learns of a secret organization that can pave the way for a possible escape.