Finally back on a grand adventure! Even though Gräte and Bumskopp drive their captain Flitschauge to the brink of madness multiple times a day, he is extremely satisfied with his two new pirates. The Unsinkable Three tirelessly create one daring plan after another. When they learn about a huge diamond treasure, there's no stopping them. The "Storm Hell" is quickly made ready for departure, and the three set sail... The crazy adventures and dangerous storms they must endure on their way to the diamond treasure are recounted in this book...