What if your favorite author turned out to be a instigative, agoraphobic shut-in encased in a toxic relationship with her husband? A crazy question, sure, but one explored with such vivid color in Josephine Decker’s entertaining psychodrama, SHIRLEY, that you yourself may start to feel a bit like its titular subject, crazed but never not entertained.

Melding the limbs of psychological horror with that of a steamy period piece and…