Hel receives an invitation to visit her estranged twin Siri at an exclusive residential sanatorium set against the idyllic setting of the Italian Alps. Tension soon rises when Hel refuses Siri's plea for help in taking care of some business by swapping places with her for a few days. Much to her horror, Hel wakes up the next day to find Siri gone. She soon realizes that Siri isn't coming back, and that the clinic is far from a place of recovery. Hel is now trapped in awaking nightmare in which no-one is who they seem to be and everyone believes that she is Siri. Surrounded by the most predatory and manipulative people imaginable, escape is now only the second order of business; Hel's first problem is simple: survival...