Three siblings, bound together in a toxic codependency by a dark secret: Night after night, Dwight goes out to hunt people. But it isn’t his hunt; it isn’t his insatiable thirst for blood. Dwight hunts for his younger brother Thomas, who seems to be suffering from a mysterious illness, and for his sister Jessie, who tries to keep Thomas under control at home—whatever the cost. Director Jonathan Cuartas has created a dark, melancholic family drama with horror elements that has not only been invited to numerous festivals but has also won several awards there. Despite all the vampire tropes, the quiet, dark production relies less on shock moments than on psychological tension, carried by strong actors who make their despair in isolation more than palpable and draw the viewer deep into a vortex of family responsibility, guilt, and self-sacrifice. “My Heart Can’t Beat Unless You Tell It To” is a sophisticated independent horror film that could not have been made more effectively or with greater impact.