Lauren Schafer and David G.B. Brown star in this US thriller. The film follows Rachel (Schafer) as she finds herself submerged in a frozen lake and struggling to survive. As her oxygen supply rapidly depletes, it is revealed that Rachel has been attacked and left for dead by her husband Ben (Brown), after finding out he's a serial murderer. The film chronicles how the pair met and arrived at this point, with Rachel desperately fighting for her life in the frozen lake and Ben stalking her from the surface.