The horror, the horror…
The vocabulary is literal. So, the problem becomes for the movie maker, how do I take this literal vocabulary and find a representative image for something that is so outside the realm of any human experience? ~Sidney L. Lumet, director of The Pawn Broker 
In this installment of my three part series we will continue the discussion of the evolution of the media depiction of the Holocaust via a comparison and contrast of two recent European films: Gilles Paquet-Brenner’s 2010 movie Sarah’s Key and Nicolas Klotz’s Heartbeat Detector by bringing to our attention the dramatic use of horror as a quality necessary for the effective portrayal of the Nazi [in particular] crimes against humanity of the Second World War.
[This is your fair warning, a certain amount of the two movies Sarah’s Key and Heartbeat Detector will be revealed, that you might not want to be revealed if you haven’t watched the movies]
There is a certain quality that any movie that attempts to take on the subject of the Holocaust seriously must poses if it is not to fall flat, to fail in its responsibility to its audience, that is horror. The horror the film maker is aiming for needs to be a type of psychological horror that the audience can perceive strongly enough to be able to distinguish what was truly unique and unprecedented about the holocaust, that it was something so vast and evil we could ordinarily never have conceived of it, from the more ordinary and human tragedy that we see in other subjects filmmakers turn their lenses to. The holocaust was something so horrific, only horror can shed light on it. At the same time we also need to be shown that there are patterns and traces of the holocaust permeating history right up to the present day, and back further through history.
Hard to do.