Robert Louis Stevenson, celebrated author of Treasure Island  (1882-3), Kidnapped (1886), and "The Strange Case of Dr. Jekyll and Mr. Hyde" (1886) was a lifelong connoisseur of "penny dreadfuls": illustrated serial fiction that targeted working-class readers. In Stevenson's childhood, his nurse Alison Cunningham often read dreadfuls to him. In adulthood, Stevenson was haunted by one serial in particular. This was A Mystery in Scarlet by “Malcolm J. Errym,” the pseudonym of James Malcolm Rymer (1814-84).