This colorful Swede, the great fighter of plagues, is Sinclair Lewis’ own creation, having no prototype as so many of his characters do. It is notable that Arrowsmith was not mentioned when Lewis received the Nobel Prize at Stockholm, perhaps because Sondelius did not give a flattering picture of the Swedish scientist. Impulsive, energetic, and hard-drinking, he nevertheless inspired Martin in the early stages of his career and became his servant later on. With reckless disregard of his own health, Sondelius refused to be inoculated with the phage until all the islanders were similarly protected. Consequently he had no protection when the plague struck him and perished on the island of St. Hubert. Although his knowledge of medicine is more superficial than Martin’s, he is a good mixer, a sincere and enthusiastic worker, and with his extrovert qualities a foil for the studious and withdrawing Martin. Sondelius was a favorite of Lewis himself.