Not just a predictable "possession" story, or a rehashed "ghost story". A retelling of classic cautionary tales to stay in your depth and hold your course. It does very well with the ideas in old sailor's tales of ghost ships, sirens and sea witches. They are all predictable, like the tides; once a siren is on you, you are done. Maybe its only a simple life-to-death allegory, but no one escapes a sea witch. (Except animated Disney princesses)