"Infiltration" follows an alien fugitive living in New York under the name Mister Disbrough, a being who can dissolve his human shape into that of a wolf and back again, and who has spent the story's single evening aware that his enemies are closing in. Waking at sunset out of habit rather than superstition, he goes through a mundane routine—shaving, grooming in wolf form with combs screwed to his bathroom door, listening to a Giants broadcast, making coffee—while his thoughts unspool the true history of his species and, with it, of the human race. Budrys reveals that Disbrough and his kind are members of a marooned alien expedition, stranded in this universe for what amounts to roughly half a million subjective years (about six months of "real" time) while awaiting a shift in the "paramathematical path" that will let them go home. Unable to survive that span directly, they encased themselves in self-sustaining, self-reproducing organic shells called chrysalids, each housing a dormant sleeper who is passed unknowingly from host to host as bodies wear out. To guard against the path shifting unnoticed, one aware "Watcher" was meant to wake in each generation—until suspicion arose that a Watcher might exploit his monopoly on power over the helpless sleepers, so rival Watchers were set to watch each other, and a dissenting faction, contemptuously named "Insurgents," began waking at random instead, trusting to chance rather than hierarchy. This schism, not any inherent malice, becomes—in the narrator's bitter reconstruction—the hidden engine of human history. Watchers colonized human chrysalids exclusively; Insurgents inhabited wolves, bears, tigers, bats, seals, and other animal hosts, which is the actual origin of the werewolf legend: an Insurgent forced to fight a human-shaped Watcher on equal terms by adopting human form himself, "without hair on his palm, and with garlic on his breath, if he so chose." Every human institution of tribalism, segregation, nationalism, and war—he cites Rome, Napoleon, Nazi Germany, lynching, the back of the bus—is recast as the by-product of these two alien factions maneuvering to control blocks of chrysalids, walling off "pens" of population to secure obligation over the sleepers within. Weapons technology from ballista to atomic bomb progresses only because the chrysalids, driven by the same power struggle, had to keep learning to survive it. Yet the narrator refuses to let this metaphysics erase human achievement or agency, wondering at Beethoven, Shakespeare, and Rembrandt as things the "mere" chrysalids produced on their own, independent of Watcher or Insurgent design, and reproaching his own kind—both sides equally—for the greed and suspicion that set the "juggernaut" of war rolling. Domestically, the story stays small: Disbrough gets a tip-off call from his apartment building's doorman, Artie, that two men are coming up, calmly gives away his liquor, dresses by reshaping his chrysalis into the illusion of clothing, and lets in two FBI agents. They lay out an airtight espionage case against him as a foreign agent (the human-level cover story for his real, alien mission), and, feeling out of place in that frame, he simply offers to confess to everything on their list. What he actually wants is not to escape but to be brought before whoever runs the operation, because he can literally scent that a Watcher is nearby, and he wants to force a confrontation. When the Watcher is brought out to witness the "confession," Disbrough recognizes him by smell and mockingly greets him as "brother," toying with the idea of coalescing into wolf form in front of the human agents purely to terrify the Watcher into exposure—an act that would blow the secret war into public knowledge for both sides. The Watcher, panicked at the thought of rumors spreading and the chrysalids someday learning "the origin of their species," is forced to respond in kind. In the story's climax, Disbrough deliberately provokes his own death: he advances on the Watcher, is shot by a bystander agent, lunges forward anyway to "hold the Watcher to his debt," and is finished off by the Watcher's gunfire. Dying, he reflects with something close to tenderness on the possibility that this enemy might literally be a brother-sleeper he has fought and reconciled with in other bodies across ages he cannot remember, and hopes that when all the sleepers eventually wake, the memories of endless mutual slaughter, disguised across human history as ordinary wars, will be mercifully erased rather than carried into whatever peace or reunion awaits them. He dies murmuring "Thank you, brother," framing his own killing—paradoxically—as a small, personal victory scored against the Watcher he has bound by an act of violent, self-sacrificing obligation. The story closes on that ambiguity: an alien secret history offered as literal explanation for humanity's tribal violence, undercut throughout by the narrator's own guilt, weariness, and hope that this shadow war, seen from outside eternity, might ultimately mean less than the human civilization it inadvertently produced.
By Algis Budrys · First published 1958 · Genre: Science Fiction, Espionage Thriller, Fantasy · 2 chapters