Having just finished the book about the Heydrich assassination, I started HHhH, a "nonfiction novel" about the same thing, which so begins fabulously it reminds you why people write, why people read, and why some people bother to live at all.
In English, of course, the title is pronounced 'aitch aitch aitch aitch.' In German, however, it's 'ha ha ha ha.'
I find that kind of eerie.
The Hs stand for 'Himmlers Hirn heisst Heydrich,' meaning 'Himmler's brain is named Heydrich.'