A documentary's potency is usually measured on two levels: the ability to convey information, and its power at swaying you emotionally. When a filmmaker accomplishes both, they truly have something precious to share with others, but striving to do one or the other well can also be acceptable provided you still feel different walking out of the theater.
And with Blind Spot – Hitler's Secretary one would expect to feel some kind of metamorphosis exiting the 90-minute collage of interviews. Here was an individual who not only worked for the famous dictator for years but was able to bid farewell to him in his last hours. To this day there are rumors and assumptions bandied around about the man's private affairs, hypothetical observations that can often be supported only by vague but strongly-worded theories from historians that rarely get verified. And here was (may she rest in peace, she died shortly before the film's premiere in Berlin) a living, breathing witness to some part of the behind-the-scenes, a unique opportunity.
See filmcritic.com for full review.