A confessional narrative from a mad scientist Dr. Therne obsessed with one of the great issues of his day... in this case, vaccination against epidemic diseases like smallpox. His personal fears meet the tragic legacy of other doctors' careless ignorance and spawn a malignant crusade against vaccination that will ultimately create many more victims. Henry Rider Haggard writes to alarm and educate his public, and creates a very engaging villain to carry his message.