Spoilers *Kidnapping*
Overall I was pleasantly surprised by this - I accidentally netflixed this instead of a similarly titled movie, and I ended up thoroughly engrossed and creeped out.
HOWEVER, there were several plotholes that took me out of the story, primarily how the psychopath was able to kidnap Mina - uh, she was shown several times riding a bike, or walking. Never driving a car. So, how did she get Mina into her torture basement? On the handlebars? Also, the husband MUST have known about her. Did he help her mutilate and torture victims? And how was it her fault if he ALLOWED her to chop his arms off? Her limp seemed like a non sequitor too, unless I missed something. And, lastly, the end was just a bit much. An unstaffed hospital, a serial killer who escapes unscathed and barefoot from the basement of a burning building and magically appears in a hospital bed, etc.
They're coming to get you, Barbara!