Times Without Number
John Brunner
 In 1988, Don Miguel Navarro is a "Licentiate in Ordinary" of the Society of Time. As a Licentiate, Don Miguel's primary duty is to ensure the preservation of history, lest an alteration undo the empire. While at a party held by the Marquesa di Jorque, his hostess shows off a gold Aztec mask she had recently received as a gift. Recognizing it instantly as contraband, Don Miguel launches an investigation that eventually leads to the unmasking and arrest of Don Arcimboldo Ruiz, a prominent nobleman (and a cunning and skillful villain) engaged in the illegal acquisition of goods from the past. Don Miguel is then entrusted with returning it to the exact spot in the past from which it was taken, in time for it to be used in the Aztec bloody rites of mass human sacrifice - with which he is duty bound not to interfere but which leave him shaken. Because of his success, Don Miguel is honored and marked as a coming man. Some time later, while attending a New Year's Eve ball at the palace of the Prince of New Castile, a prince of the blood and the Commander of the Society of Time, Don Miguel meets Lady Kristina, the daughter of the Swedish ambassador. At her prompting, the two leave the party to explore the city of Londres for themselves. While walking down one of the city's streets, however, they encounter an unusually dressed woman who is assaulted by men who intend to rape her, but turns out be more than able to take care of herself, proceeding to immobilize a number of her assailants before Don Miguel is able to knock her unconscious (the reader can easily recognize that she is adept at some kind of martial art, but in Don Miguel's world these are unknown in the West). Taking the woman to the Society's headquarters, he attempts to return to the prince's palace in search of Father Ramón, the society's master theoretician, but is stopped by a panicked mob clogging the streets. There he learns of the burning of the palace and the deaths of all of the assembled dignitaries at the hands of dozens of female warriors (transported, it turns out, from an alternate timeline in which a Mongol King rules all of Asia and Europe and which senior members of the Society of Time secretly contacted). After encountering Father Ramón, the two return to Society Headquarters, where they use a special cross-temporal Mass to contact an earlier version of Father Ramón and prevent the massacre from taking place. However, though seeming to end well, the episode leaves Don Miguel with a mounting feeling of anxiety, having found out that his superiors engage in dangerous experiments and realizing by what a thin thread the entire reality he knows hangs. Needing a vacation, Don Miguel travels to California, a backwater rarely visited by Europeans. While relaxing at a hacienda near a local mine, his host, a Native American engineer named Two Dogs, shows him a steel bit from a rock drill discovered in a recently started mine. (In this timeline, there had been no California Gold Rush and gold mining is a governmental monopoly.) Fearing a violation of the treaty between the Empire and the Confederacy of the East regulating time travel, Don Miguel alerts the Society, which launches a full-scale investigation. When Father Ramón arrives on the scene, however, he insists that no violation has taken place, even though a scouting expedition confirms that there is indeed a group from the 20th Century mining the land in the past. Traveling to the site, Don Miguel and Father Ramón converse with the leader of the group and convince him to end the operation; Father Ramón is clearly determined to defuse the tension and avoid at virtually any price an escalation in the two great powers' relations. The reason for that becomes clear upon their return: Don Miguel finds out that the "discovery" had in fact been planted by Two Dogs, who is spearheading a conspiracy of anti-Mohawk native Americans seeking to bring down the Empire, and who manipulate the Eastern Confederacy and make use of it but have their own far-reaching agenda. In the ensuing melee, Two Dogs escapes and Father Ramón is killed. It is assumed that, having failed in his carefully crafted plot, Two Dogs would seek to travel into the past and deal the Empire's past a grieveous blow. Determined to preserve their history, the Society sends Don Miguel and dozens of other Licentiates into the past to prevent Two Dogs from disrupting the pivotal event of the Armada, but while undercover in 1588 Cadiz Don Miguel discovers to his horror that Two Dogs has already succeeded; Parma's second-in-command, the military genius Earl of Barton, no longer exists - having evidently been assassinated by two Dogs while still an obscure young adventurer - and Parma himself is no longer the commander of the fleet. Urgently rushing back to the present, Don Miguel hopes to still sound a last minute warning - but is overtaken by the forwardly proceeding wave of changing reality (a highly painful experience) and arrives not in New Madrid but its analogue, New York City, emerging in Central Park to the amazement of passers-by. From this Don Miguel realizes that people of the changed timeline have no knowledge of time-travel, which would have given them a clear explanation for a man appearing out of thin air, and that he is the only person in this timeline who knows the secret of time travel. Reflecting upon this he concludes that timelines where time travels exists eventually collapse on themselves, when somebody changes the reality leading to the invention of time-travel itself. He decides to accept developments as God's will and to begin a new life as "the most lonely of all exiles" in the world where he now finds himself, keeping time travel a secret and never disclosing his knowledge of how to build a working time machine. And meanwhile, Two Dogs' ruthless act against the Empire turns out to have boomeranged against Two Dogs' own people, creating a timeline where Native Americans fared much worse than in the one he destroyed.