Narathorn is a marine biologist who is researching artificial reefs. He found a perfect coral reef, but it's dangerous because it has a vortex that can not be explored. While the work of Narathorn is ongoing, someone smuggled the coral. No one knows that it caused the soul of Sarai, a girl murdered a few years ago whose soul settles in the coral, to be released. She comes out during the night to suck the blood of helpless humans.
—Vorachote Sakulsri