When Jack was invited to join Serena and her parents on a lengthy, luxury cruise, the holiday turned out to be a bit more exciting than bargained for. And even though Serena and Jack are gifted with those supernatural powers which proved invaluable in their fight against Beelzebub and his evil accomplices (Sleepwalkers Children of Crystal), their unique powers were of little use when they found themselves in the clutches of hardened criminals. However, looking on the bright side, their deep love for each other didn't stop them - when the smallest opportunity arose - from doing what all hot-bloodied seventeen- and eighteen-year-old sweethearts do, presumably . . . hmmm?