
Extraterrestrial parasites grant two scouts extraordinary abilities, but their deadly final form forces one man into a high-stakes hunt to destroy his former friend before humanity is consumed.
In Short
Charles V. De Vet’s sci-fi story follows Max Calof, an operative hunting his former survey teammate Howard Zealley across Earth. Infected by microscopic alien symbiotes on an unmapped planet, both men gain heightened intelligence, rapid physical healing, and sleepless vitality. However, the parasites are destined to mature into ravenous, flesh-eating winged insects that could wipe out human life. To prevent a galactic catastrophe, Max tracks the elusive Zealley through an unfamiliar city, risking his own life in a quiet, deadly battle of wits and endurance to eliminate his transformed companion before time runs out.
The Story
Max Calof arrives in an unfamiliar city, weary after eight years of relentless searching. He checks into a low-end hotel room under his real name, hoping his former partner, Howard Zealley, will take the bait. Years earlier, while surveying planet TR768-L-14 for human colonization, both men were bitten by unidentified organisms. Initially, the infection seems like a miracle: their mental processes sharpen, their physical strength doubles, their wounds heal almost instantly, and they no longer require sleep.
The Space Bureau’s medical teams discover the organisms are benevolent symbiotes. However, subsequent laboratory testing reveals a horror: at the end of a decades-long cycle, the parasites evolve into winged insects that devour their human hosts from the inside out before flying off to infect others. Realizing the danger to all humanity, Zealley flees to Earth, using his heightened intellect to go into hiding. Max, trusted by the authorities for his strong sense of duty, is sent after him with forged credentials.
Max methodically narrows down a list of prominent local citizens using the hotel's information service screen. He targets an industrialist named Russell Baker and delivers a deliberate message to Baker's sleek, indolent secretary, John Roesler, mentioning Zealley's name. Soon after, Max notices he is being shadowed by a pale-faced youth. Knowing a confrontation is imminent, Max prepares a hidden alarm system in his hotel room using electrical wires and a black box device.
Three men burst into Max's room: a dark-haired enforcer named Steve, the knife-wielding youth named George, and Roesler—who wears a yellow hat and casually trims his nails with a penknife. Roesler forces Max to strip, revealing Max's glowing, phosphorescent skin in the dark. Max observes Roesler's superhuman reflexes and realizes that Roesler is actually Zealley, who has altered his physical appearance through his connection with the symbiotes. Zealley taunts Max's devotion to duty while letting his thugs attack.
Although Max is badly stabbed in the stomach during the melee, he manages to overpower the henchmen just as his preset alarm brings the police to the room. Max frames Zealley and his men for the attack, forcing the police to haul them away. Severely wounded and in agonizing pain, Max flees the hotel before an ambulance arrives, knowing his symbiote will take hours to repair the deep internal damage.
Fighting off debilitating muscle cramps, Max rents a sixth-floor office facing the industrialist's headquarters. Assembling a rifle from his bag, he patiently waits at the window. When a taxi drops off a man wearing a yellow hat, Max aligns his sight and fires a single lethal shot.
A year later, Max returns to New Nebraska after securing passage with a changed body. There, scientists reveal a new discovery: blood transfusions can reset the symbiote's life cycle indefinitely, allowing humanity to safely enjoy its gifts. Max reflects pityingly on Zealley, whose selfish impatience prevented him from surviving to see the ultimate cure.
How It Unfolds
The search narrows Max Calof checks into a cheap hotel room and uses a networked information screen to filter down a list of sixty-four local men between twenty and forty years old, determined to draw out his former friend.
Setting the trap After leaving a direct message with a wealthy industrialist's secretary, Max notices he is being followed and returns to his room to rig a covert alarm using the electrical light fixtures.
The target revealed Three confrontation-seeking men break into the room, led by the secretary John Roesler; when Roesler displays impossibly fast physical reflexes, Max realizes his target has altered his face and identity.
A painful standoff Max stalls for time as Zealley mocks his sense of duty, but a thug stabs Max deeply in the abdomen right before Max's rigged alarm brings the police knocking.
The final confrontation Bleeding heavily, Max slips away from the hotel, sets up an ambush in a rented upper-story office across from his target's headquarters, and shoots Zealley dead as he steps out of a taxi.
An ironic ending Max returns home a year later to learn that scientists found a simple blood-replacement method to safely control the symbiotes, rendering Zealley's desperate betrayal completely unnecessary.
The People
- Max Calof: A dedicated survey operative driven by a deep sense of responsibility. Enduring a painful, eight-year hunt across alien worlds and cities, he willingly suffers severe bodily harm to track down his former partner and protect humanity from a deadly parasitic outbreak.
- Howard Zealley (John Roesler): Max's former surveying teammate, an exceptionally clever and imaginative man whose core egotism drives him to flee when he learns the parasites inside him are fatal. Taking on the alias of a smooth, manicured executive secretary, he uses his altered physical appearance and heightened intellect to pull strings from the shadows.
- George: A young, flat-eyed street thug employed by Zealley. Quick to pull a switchblade knife, his impulsive violence causes Max a near-fatal stomach wound during the hotel room ambush.
- Steve: A lean, dark-haired enforcer with a bent nose who assists Zealley in trapping Max, using brute physical force to strike Max down from behind.
In Its Own Voice
"The man I searched for could be anybody at all. If I didn't find him, there'd be nobody at all."
Max reflects on the existential stakes of his search while checking into a cheap hotel cubicle to begin his elimination process.
"During the next several weeks of flight, Zealley wrote a historical novel that I was certain would turn out to be a classic. I found myself mastering, without difficulty, higher math..."
Max recalls the initial, exhilarating period following their infection on TR768-L-14, when the microscopic organisms dramatically expanded their mental capacities.
"The hogs, the smart boys who have every angle figured in getting the jump on everybody else--how is it they never figure the last angle?"
Back on New Nebraska, Max ponders the tragic irony of Zealley's fatal impatience after learning that scientists had successfully neutralized the parasitic threat.
What It's Really About
At its core, the narrative contrasts self-sacrificing civic duty with self-serving opportunism. Max and Zealley are given identical gifts and burdens: expanded intellectual capacities, physical resilience, and the horrifying knowledge that their alien parasites will eventually kill them and destroy humanity. Where Max accepts his obligation to eliminate the threat regardless of personal cost, Zealley uses his gifts to manipulate others, hide in luxury, and escape accountability. The story questions whether intelligence and power inherent in rapid human evolution mean anything without an accompanying moral compass. Ultimately, it argues that selfish cynicism often overlooks the simplest, most vital solutions by assuming every situation is a zero-sum game of survival.
Why Read It Today
Readers who enjoy vintage mid-century science fiction with noir sensibilities will appreciate this concise, fast-paced tale. It reads like a hardboiled detective story cross-pollinated with alien biology tropes, featuring low-lit hotel rooms, quiet street tailing, and ruthless back-alley ambushes. The plot moves cleanly from one tactical decision to the next without pausing for unnecessary exposition, making the lead character's physical suffering and mental fatigue feel palpably grounded.
The story reflects period attitudes toward space travel and body horror typical of 1960s magazine fiction, treating massive interplanetary distances and bio-engineering with pragmatic simplicity. While modern readers might find the narrative's sudden resolution swift, the dark irony of its final twist delivers a satisfying conclusion that stays with you long after reading.
This summary was written by AI (g4f/auto) on 2026-08-31 and is a guide to the book, not a replacement for it — it can be incomplete or wrong. The book itself is public domain. Copyright & AI disclosure · Report a problem





