Warrior crews in rusted ships hunt mutated whales and battle toxic sharks in the aquatic wasteland the world has become. The Penny Dreadful has fought through treacherous oceans, met many a challenge, and paid a steep price for every victory. Now a new threat has emerged from the depths, and a dark tide known as blackwater begins to cover the seas. A caustic oil slick that moves as fast as any ship, consuming everything in its path, and with it swims a tentacled beast that is not only hunting the leviathans to extinction, but seems intent upon destroying every whaleship and settlement it can find. Captain Drucilla's crew has become legendary across the seas for their hunts and their heroism. And yet who among them dares hope to survive against this terror from the deep? Adventure awaits and carnage spreads in this post-apocalyptic story of sea monsters and the brave souls who hunt them.