Love the Quantz stories, and from Fritz' letters to Wilhelmine, I remember that there were ups and downs even during the crown prince years. Also, Quantz' direct quote is lovely, particularly the German phrasing. It keeps being interesting that Fritz could have that effect on people. (Even Heinrich, kind of. :P)

"Non, mon ami, le tyran demande du sang" - seeing the context in your other comment, i.e. not coming back soon, one could interpret this as him speaking metaphorically, about imprisonment/physical punishment? Possibly?