Characters in horror movies usually work to keep demons away. In A Dark Song, it’s the opposite. As you can see in this first trailer, when two characters tirelessly work to raise the undead, the result is as creepy as it is surprising.
A Dark Song is about a woman who recruits a man to help her complete a very long and complicated ritual of black magic. If done successfully, she’ll get to right a terrible wrong from her past. If mistakes are made, the ritual may make her accessible to demons from all eternity. It’s quite the gamble.