Eerie and utterly riveting, this documentary by Israeli director Vanessa Lapa uses recently unearthed correspondence from Heinrich Himmler to show the home life of the man who ran Hitler’s SS. Actors read the letters Himmler exchanged with wife Marga, daughter Gudrun, his mistress and his parents, even as his men slaughtered Jews and all other “undesirables” across Europe.

Archival footage and family photographs play under the readings. A few times Lapa underlines an irony too heavily, but otherwise the technique is remarkably effective.

The film can’t explain why Himmler, the skinny, awkward boy, became a mass murderer. But the letters Himmler’s father wrote to intercede for friends whose loved ones were being imprisoned, and the diary kept by little Gudrun — a daddy’s girl to the end, as the movie shows — will haunt the viewer for a long time.