From the back of the book:
"A strange seaborne adventure designed for the Pathfinder RPG, with scaling options for 4-6 characters of 5th-7th level.
Welcome to the weather-beaten deck of the Green Lady, a galleon adrift on the blue-green waves... but where is her crew? Where is her legendary captain, the self-exiled wizard, Vossian the Green? Set sail 'lubbers and find out in this, our very latest Grave Undertaking starring your characters as the daring scallywags destined to solve the mystery of The Ship of Fools. You're sure to enjoy this excellently weird horror-trip written especially for the Pathfinder Roleplaying Game, and delivered in true TPK Games fashion. Brave deadly zombies, mind-control slimes, suicidal haunts, sharks, swarms of eels and maybe your own crew (!) amongst other delightful deadlies in this rollicking good time!"