Based on the Sega Genesis game of the same name.
Taking place in the New York City during the late 1920s, when cult leader Henry, the gangster Al Capone (Vincente DeMarcoto in the American localization), and a sorceress named Restiana plot to awaken the ancient and malevolent god Hastur. There are some people that have descended from Hastur's ancient bloodline, one of which is the young Peruvian sorceress, Annet Myer. With some assistance from Earnest Evans, Annet attempts to stop the cult from resurrecting Hastur using the very spells of this bloodline.
Unfortunately the manga was never finished, and ends on a cliffhanger.