A Barnstormer in Oz: A Rationalization and Extrapolation of the Split-Level Continuum is a 1982 novel by Philip José Farmer and is based on the setting and characters of L. Frank Baum's The Wonderful Wizard of Oz.
The central character of the novel is Hank Stover, a pilot and the supposed son of Dorothy Gale, who finds himself in Oz when his plane gets lost in a green cloud over Kansas in 1923. The Oz he discovers is on the brink of civil war; he encounters Erakna, the new Wicked Witch.
Farmer takes an unusual approach to the corpus of Oz literature; he depends primarily, almost solely, on Baum's original Oz book and neglects its many sequels. This "originalist" approach to the Oz mythos is rare but not unique; a few other writers — perhaps most notably, Roger S. Baum — have taken similar tacks. In Barnstormer, Dorothy has made only one visit to Oz; when Hank Stover arrives, the Scarecrow still rules the Emerald City, just as at the end of Baum's first Oz book.
Since Farmer wrote for adults rather than children, there are elements of sex and violence in Barnstormer that are not typical of the Oz literature. As the book's subtitle indicates, Farmer indulges a rationalizing and explanatory bent: he treats Oz as a parallel universe in the science fiction vein. He attempts explanations and analyses of some of the fantastic elements in Baum's fictional world, including magic and talking animals. The book is also subtlly anti-socialist, the character constantly points out the flaws of the near communist Oz. Others have projected a gun-control view on the book. Gunpowder and firearms are outlawed by the ruling magicians as they believe it would cause an upset of power and allow their subjects to level the playing field.
Inevitably, critics have disagreed on the value of Farmer's contribution to the literature of Oz. Jack Zipes called the novel "splendid," while Katharine Rogers considered it "revision to the point of debasement."
Farmer wrote several other books that take fresh views of famous figures of popular and pulp literature: A Barnstormer in Oz can be grouped with his Tarzan Alive: A Definitive Biography of Lord Greystoke (1972), Doc Savage: His Apocalyptic Life (1973), and The Other Log of Phileas Fogg (also 1973), among other works.