Setting out towards the next Guardian's Tower, deep into the sea――! Upon arriving at a fishing village where rumors say, "I saw a castle at the bottom of the nearby sea," they find it transformed into a desolate village shrouded in unnatural thick fog, teeming with undead! Kena protects the only girl left in the village, Luka, and challenges the ghost ship and the pirate captain to battle in order to clear the fog――!!