From the back of the book:
"A body lays facedown before a set of doors, in the passage ahead. The once crimson vestments that dressed the dead monk of Theydori were soaked with dark blood. My companions turned the monk over; the left side of his skull was collapsed, having been struck a tremendous blow.
While the others attended to the dead monk, my attention was firmly fixed upon the nearby set of doors, hanging slightly ajar. An unnatural radiance pulsed within the room, accompanied by the beat of a feint tone, the likes of which I have never heard in the waking world..."
A simple sea voyage to the remote island of Guardian quickly becomes a terrifying fight for survival as an unseen foe sends its minions against you in a bid to consume your very souls!
Dark Awakenings: Guardian is a d20 adventure for 4-6 characters of level 3-4 that is continued in Dark Awakenings: Shadowland.