Bloodstream offers a useful occasion to think about horror as a circulation of images: what enters a scene, what spreads and what cannot be contained once seen. Keep close track of whose perspective organizes the violence and whether the film gives its victims more than a place in an effects sequence. In modest horror productions, a change of viewpoint can matter more than a larger set piece. The title's bodily suggestion makes sound, cutting and the handling of aftermath particularly useful things to watch.