The book's frame narrative and premise is that "after dabbling in radical politics", Adolf Hitler emigrated to the United States in 1919 and became a science fiction illustrator, editor and author. He wrote his final science fantasy novel Lord of the Swastika in six weeks in 1953, shortly before dying of cerebral hemorrhage (possibly caused by tertiary syphilis); Lord of the Swastika subsequently wins the Hugo Award and the "colorful uniforms" described therein become a regular feature of cosplayers at science fiction conventions. Hitler's other published works include the long-running fanzine Storm and the novels The Master Race , The Thousand Year Rule , and The Triumph of the Will .
In Whipple's review following the narrative, we learn more about the background of the alternate history in which Hitler emigrated to the United States. Without Hitler's leadership, the Nazi Party fell apart in 1923 and the Communist Party of Germany succeeded in fomenting a German communist revolution in 1930. As this alternate history continues, there is reference to a "Greater Soviet Union" which took over the United Kingdom in 1948, and whose influence is growing in Latin America by 1959. The fact that Whipple refers to World War I as "the Great War" implies that there has been no equivalent of World War II in this world. The core element in the historical backstory of Lord of the Swastika of a nuclear apocalypse but Whipple gives no indication about such weapons existing in this alternate reality. In fact, Wells "The World Set Free" (1914) also theorized about atomic bombs so no conclusion about their existence or even their technologically plausibility in this alternate reality can be made.
Whipple also discloses that Japan has retained its militarism, with reference to its bushido code of conduct, while the United States vacillates against the Greater Soviet Union's ascendancy. Due to the Greater Soviet Union threat, the United States and Japan have moved towards a closer military and strategic alliance. Japanese militarist values are much admired in the United States. Japan and the United States are the only two major powers standing between the Greater Soviet Union and total control of the globe—yet most Americans seem unable to be roused to deal with the Soviet threat. Whipple wonders what the emergence of an American leader like Feric Jaggar, the hero of Lord of the Swastika , could accomplish. Finally, there is a casual mention of the fact that, while in this history Nazi Germany never came into being, it is the Soviets who have undertaken the systematic genocide of all Jews in Europe—and since this is perpetrated by the Soviets, there is no power left whose armies might stop it and save at least a remnant of the Jews from this version of the Holocaust.
Lord of the Swastika is lauded for its qualities as a great work of heroic fantasy. To further hammer the point, in an early edition, actual science fiction writers wrote faux sincere "admiring" blurbs for Spinrad for the novel's back cover blurbs, praising "Hitler's" writing skills. Irony abounds in Whipple's review, as he argues author Hitler is obviously wrong in assuming that not much more than midnight rallies and phallic symbolism would create a large number of supporters for a movement. "After all", Dr. Whipple says, "it can't happen here."
Lord of the Swastika opens in the year 1142 A.F.—"After Fire", the global nuclear war referred to as the "Time of Fire" which brought about the end of the civilization of the technologically advanced "Ancients" and the current despoliation of most forms of life. The gene pools of almost all life forms are corrupted by the radioactive fallout. Few examples of the baseline human form can be seen, and most of humanity are mutants with blue skins, lizard scales or parrot beaks, or wizened half-breed mutants and normal-seeming but inhuman "Dominators", who desire to rule the ruined world with their mind-controlling powers.
The pure and strong young "Trueman" (so named for the lack of mutations in his DNA) Feric Jaggar returns from the outlands of Borgravia where his family was exiled by the treaty of Karmak with the surrounding mutant states to his ancestral land of Heldon ("the High Republic of Heldon"; founded on the principles of killing mutants and keeping humanity pure), only to find its rigor slackened and corrupted by the "Universalists", pawns of the sinister Dominator country Zind, which seeks to corrupt Heldon's pure human gene pool into the mutant diversity that rules the rest of the world. Indeed, in the very first portion of Heldon that Feric enters, the customs fort where entrants are tested to see whether they are pure and free of mutation, he is outraged that mutants are being allowed into Heldon on day-passes, that the fort is under the spell of a Dominator, and that the tests are so lax that impure specimens are being granted citizenship.
In Heldon proper, Feric dines in the "Eagle's Nest" tavern, and mulls over the question of how to change this situation. Should he enter politics or the military? Feric then witnesses the oratory of Seph Bogel, leader of the Human Renaissance Party, who speaks eloquently but ineffectually to the crowd about the need for human purity. Fired by his words, Feric is inspired to take control of the listening crowd and leads a mob to the same border post, there to slay the Dominator (or "Dom") who had quietly disguised himself as a clerk to sway the immigration decisions in favor of mutants. At Bogel's invitation, he assumes leadership of the Party, which Feric later renames The Sons of the Swastika, and the two travel on to Walder—the second city of Heldon—to meet the party inner circle and begin the great task.
Their journey is interrupted when their steam-powered vessel is waylaid by the outlaw petrol-powered motorcycle gang, the Black Avengers. Jaggar, however, senses that these men may be of use to his cause and challenges their leader, Stag Stopa. The rules of the Black Avengers only allow a member to challenge the leader, and so he and Bogel are taken back to their headquarters for Feric to be initiated. Feric acquits himself mainly in the drinking of ale and in running the gauntlet of torches on a motorcycle. He and Stopa duel with truncheons, and Feric's truncheon breaks. Desperately he reaches out and defeats Stopa with the legendary "Great Truncheon of Stag Held"—which may only be wielded by a descendant of the last true King of Heldon, Sigmark IV. The Black Avengers immediately pledge fealty to him, and become the "Knights of the Swastika".
From this event, Jaggar assumes a hereditary right to be the leader of Heldon and embarks on a violent crusade for genetic purity, drawing a massive following, staging outdoor rallies and raising an army personally loyal to him. He is elected to the Council and stages a coup d'état when he forces the Council to admit to treason and a Zind plot against Heldon. Confirming his suspicions, the Universalist member of the Council turns out to be a Dom. Feric summarily executes him with the Great Truncheon. Jaggar coerces the Council into granting him complete executive power and then has them shot. Immediately after assuming power Jaggar puts down an imminent coup by Stopa, who has been corrupted by the fleshly pleasures of Zind.
Backed by the army and the adoring multitudes, Feric sets about the great task of re-invigorating the military, ordering the production of tanks and fighter jets, the establishment of the Swastika Squad (SS)—a legion of the purest and most manly men that can be found via the "Classification Camps," which examine all citizens of Heldon (killing the Doms and sterilizing or exiling all relatively impure humans). After repelling a Zind attack through Wolack, Heldon annexes its western and southern neighbors, beginning with Borgravia. In the course of the Helderisation of its neighbors Jaggar orders, at the suggestion of Bors Remler, that all mutants are to be euthanised rather than exiled.
Months later, his scientists report that they are near to rediscovering the secrets of atomic bombs, but that Zind is making efforts to dig up relics of the Ancients, which might salvage its own complement of nuclear weaponry. Noting the damage such weapons had done, Feric orders such research ended, and determines to wipe out Zind and every last Dom before they can unleash the Fire. Soon enough, Zind begins to rally its troops from their reverse in Wolack. The final invasion of Zind is hard fought: the main Helder force, under the command of Lar Waffing, takes the southwestern oil fields needed for resupply, while the secondary force fights a delaying action against the vast bulk of the Zind army to the north towards the Zind capital, Bora. Needless to say, the forces of Heldon prevail and the Zind army is destroyed and burned, down to the last mindless "Warrior". The central city is reduced to a cinder in a firestorm (akin to the bombing of Dresden in our world).
The last Dom, apparently a military leader, is discovered hunkered down in a bomb bunker. The Dom has anticipated defeat and, before Feric has the pleasure of killing him, triumphantly reveals that the Doms had salvaged and rearmed one of the ancient nuclear weapons. It is a doomsday weapon, and he triggers the failsafe. After Feric and his cohorts have evacuated Bora, a cobalt bomb detonates, and as the Dom planned, its fallout utterly corrupts the gene pool of Heldon. If any of its citizens, including Feric, reproduce, they will produce the mutants that they had previously sought to obliterate.
Feric orders the sterilization of the entire Heldon nation, including himself, and, in a final desperate gamble, orders the SS scientists to redouble their efforts to develop the next Master Race from cloning the perfect specimens of the SS. Eventually they succeed and millions of the new master race are produced in 'reproduction works' to complete the cleansing of the Earth. At the novel's close, Heldon has mastered interstellar travel. As a consequence, an initial starship, full of 300 of these seven-foot, blond, super-intelligent all-male SS clones in suspended animation, is launched into space to initiate Heldon's own galactic empire. The SS clones also have a clone of Feric to lead them. This inaugural rocket is launched on a voyage to Tau Ceti and will become the first of many.
It is a pastiche of Hitler's own life filtered through a fantasy lens, ending not in defeat but in global, indeed galactic, dominion: the Dominators represent the Jews, Heldon represents Germany, Feric Jaggar represents a cliché, wish-fulfillment, almost Mary Sue-ish self-portrait of Hitler himself, and Jaggar's initial return from Borgravia mirrors Hitler's own birth in Austria.