Fritz Leiber 
The Casket-Demon 

“You forget, baroness, the runic rhymes of the Prussian Nostradamus, ” said Dr. Rumanescue, Vividy’s astrologist and family magician. “Wenn der Kassette-Teufel . . . ’—or, to translate roughly, ‘When the casket-demon is let out, The life of the Von Sheer is in doubt.’”