Conan Doyle’s spiritualism has been attributed to the tragic deaths of his wife and son in the early 20th century; however, his interest began years before. “The American’s Tale” (1880), a short story about a blood-sucking plant, reflects his early interest in the metaphysical; by 1924 when “The Adventure of the Sussex Vampire” was published, his spiritualism had become an obsession. Two years later, Conan Doyle published his pivotal work The History of Spiritualism.

In “The Sussex Vampire,” Robert Ferguson, a tea broker and father of two, asks Sherlock Holmes for help because he is convinced that his new Peruvian wife has been sucking the blood of their baby son. Although she is a devoted wife and mother, she was caught in this vampiric act by their nurse, who plucked up the courage to confide in her master.

Ferguson was in disbelief until he saw the baby’s wounded neck and his mother’s bloodied lips. His wife offered no explanation to her husband, but just gazed at him “with a sort of wild, despairing look in her eyes.” She had also, inexplicably, twice beaten her crippled 15-year-old stepson, Jack—her husband’s son from his previous marriage. Ferguson is appalled and beside himself with concern.

Holmes and Watson travel to Ferguson’s Sussex home to confirm what Holmes has already deduced—that a vampire has not played any part in this strange case. Indeed, he says, “The idea of a vampire was to me absurd. Such things do not happen in criminal practice in England.” Holmes, as the fictional standard-bearer for rationalism, is a clear-minded and reasoned forensic investigator who never falls for the illogical.

Once installed at Ferguson’s decaying Tudor farmhouse, Holmes engages his powers of observation. He notices first that the central room of the house contains a collection of South American artifacts, including weapons. The second clue is a lame pet spaniel, which, his inquiries reveal, was suddenly semi-paralyzed by an unknown condition. The third clue is Jack’s expression of intense jealousy and hatred when he watches Ferguson embrace his baby son.

Holmes soon announces that Ferguson’s wife is entirely innocent and that the culprit, is in fact, Jack. The boy has taken poisoned darts from his stepmother’s collection and shot them first at the dog, as a trial run, and later at the baby, attempting to kill his half-brother out of jealousy. Mrs. Ferguson saved her baby’s life by sucking the poison from his neck, and beat her stepson for his wickedness. She did not reveal the reason behind these events for fear of breaking her husband’s heart.

The tension between author and protagonist, spiritualist, and logician, runs throughout this story, and reflects the wider debate in society about spiritualism and rationalism, religion, and science, that was raging at the time.

In an ironic flourish at the end of the story, Mrs. Ferguson praises Holmes’s intellect in supernatural terms: “this gentleman… seems to have powers of magic,” she declares. It is as though Conan Doyle was proving that he could be true to the nature of his literary creation despite his own personal convictions regarding ghosts and spiritualism.

The original cover of The Strand Magazine that first featured “The Adventure of the Sussex Vampire.” The short story was first serialized in the publication in January 1924.