Her character wakes up in a hospital bed, not knowing how she got there. Flashbacks slowly reveal such secrets, but as the title has it, she's cut off from the outside world because of the virus she's told she has by the surgical-masked men who drift in and out of her room. Viewers have seen enough genre films to know she's being played, without me having to spell that out.
Because of that, the cat's arguably out of the bag before Kay lets it loose, minimizing surprise or suspense. As the doctor in charge, David Harbour ("The Green Hornet") does his best Michael C. Hall-as-"Dexter" impression to cast a spell of menace, but the narrative shortcomings make it dissipate.
With actual little story to be told, "Isolation" would work better as an episode of "The Twilight Zone," from whose template this idea surely was struck. It even contains that wicked twist ending, although odds are, this one can be guessed. —Rod Lott