In Leech, Robert G. W. Kirk and Neil Pemberton explore how this creature repeatedly surfaces throughout human history, featuring in radically different practices; from the humoral medicine of the ancients to twenty-first-century cosmetic surgery, from nineteenth-century meteorological barometer to twentieth-century biomedical tool that helped to win a Nobel Prize, the leech has been often present and always surprising. A horror and a healer, the leech has reared its head in many unexpected places and practices, revealing this creature to be among humanity’s most enduring and peculiar companions.