R yan Coogler ’s extraordinary horror entertainment Sinners opens with a sequence that hits like one of those question-mark blues chords, a what-the-hell-is-happening? clang that might be setting you up for despair or elation or both. The morning light around him looking weirdly malevolent, a young man stumbles to the door of a small country church, swinging the remains of a guitar in one hand. It’s just a ghost of a thing, really: all that’s left of the instrument is the neck, a jagged stick