As it turns out, the title for this book is hugely misleading. When I began writing about two years ago, I really thought that many of the discoveries in parasitology were of a serendipitous nature. However, after talking with my group of scholars/parasitologists and seriously evaluating some of the historical aspects of parasitology, I discovered this is simply not the case. I would say, in fact, that of all the major discoveries made in the field of parasitology over the last 150 years, no more than 5–10% can be considered as truly serendipitous. Yes, there were occasions when somebody found something, or saw something, for which they were not looking. For example, in one of my first interviews, Dick Seed pointed out that very early in the twentieth century, there were serendipitous discoveries made regarding antigenic changes in the African trypanosomes. Keith Vickerman observed, quite by accident, some sort of ‘coat’ on trypomastigotes of T. brucei in the salivary gland of a tsetse fly. He put ‘two and two’ together and came up with a hypothesis that, when tested, generated positive evidence for the presence of VSGs. Sidney Ewing discovered erhlichiosis in a North American dog by accident. Arthur Looss, while working in Egypt, accidentally dropped culture medium containing L3 larvae of hookworm on his own skin and this led him to identify the entry route for these parasites into humans.