When William Sargent’s first edition of “Crab Wars” was published in 2006, few outside the biomedical community knew of the value of their unusual blood to the research and development of a range of pharmaceuticals. Now, following a number of popular articles about the subject, far more people are aware of it, but just how up-to-date they be in their understanding is unclear. Thus, a second, fully updated edition of the book is a most welcome development indeed.