by Frank Belknap Long

Setting and Context

“The Sky Trap” is a 1941 science fiction story set in a futuristic society where people work off their aggressive impulses through controlled outlets—boxing with professional “gym sluggers” and experiencing romance through “tactile television.” The story takes place aboard the Perseus, a stratospheric weather observation ship operating 20,000 feet above Earth.

Main Characters

  • Dave Lawton: The protagonist, a meteorologist and first officer who enjoys physical combat and takes pride in his scientific work
  • Captain Forrester: The ship’s commander, concerned about maintaining order and crew safety
  • Slashaway Tommy: A professional gym slugger (sparring partner) who becomes Lawton’s loyal companion
  • Dr. Stephen Halday: A scientist whose experiments inadvertently create the crisis (revealed at the story’s end)

The Crisis Begins

The story opens with Lawton finishing his weekly weather prediction duties and boxing match with Slashaway. Their civilized routine is shattered when the Perseus suddenly lurches violently and becomes completely motionless in mid-air, suspended impossibly in space despite being a heavy metal aircraft.

The Investigation

Lawton investigates the phenomenon and makes a shocking discovery: the ship is trapped inside an invisible, spherical bubble floating through the sky. Using a plumb line, he determines that the ship is suspended at the center of this bubble, held in place by some kind of energy field. The bubble itself is made of an incredibly strong, transparent material that has apparently healed over after the ship passed through it.

Strange Atmospheric Conditions

The air outside the ship contains bizarre molecular arrangements unknown on Earth—water vapor as HO instead of H₂O, methane as CH instead of CH₄, and other alien chemical compounds. These suggest the bubble exists in an environment with radically different physical laws.

The Vegetation Horror

Within an hour of being trapped, an incredible biological phenomenon occurs: alien plant life begins growing explosively inside the bubble. Serpentine vines, purple flowers, fungous growths, and toxic vegetation spread throughout their prison with terrifying speed. The plants evolve and mature at an impossible rate, suggesting that millions of years of evolution are compressed into hours due to the alien chemical environment.

Escalating Danger

The rapidly growing vegetation poses multiple threats:

  • It releases toxic, hallucinogenic gases that drive the crew toward madness
  • The plants grow so aggressively they threaten to fill the entire bubble and suffocate everyone
  • Some vegetation develops dangerous thorns and predatory characteristics
  • A massive, evil-smelling “stench weed” towers over everything, continuously growing and releasing poisonous fumes

Crew Breakdown

The psychological pressure from the toxic plant fumes causes the crew to deteriorate rapidly. Several men attack their companions, one crew member commits suicide with a knife, and the assistant engineer leaps from the ship, impaling himself on the thorny vegetation below. Panic and madness spread throughout the ship as the men lose their grip on sanity.

Failed Solutions

Lawton attempts several desperate measures to destroy the vegetation:

  • Spraying chemical agents through the ventilation system (ineffective)
  • Sending crew members with blow guns to attack the plants (they return screaming, covered in poisonous prickles)
  • Using cosmic ray absorbers to blast neutron streams at the bubble’s base (this ultimately works)

The Escape

Just as the situation becomes hopeless, Lawton’s neutron bombardment finally weakens the bubble enough to create a breach. The ship breaks free and falls toward the Atlantic Ocean, with the pilots successfully restarting the rotary engines just in time. The alien vegetation plunges into the sea, forming a toxic, floating island.

The Horrifying Revelation

As they escape, Lawton and Captain Forrester look down at the vegetation mass floating on the ocean. To their horror, they see that animal life has also evolved within the bubble—a huge, slug-like creature crawls across the plant matter, representing what might have been their fate if they had remained trapped longer.

The Scientific Explanation

The story concludes with a revelation about the bubble’s origin: Dr. Stephen Halday, working in his Appalachian laboratory, has been conducting atomic experiments that accidentally create these floating bubbles in the stratosphere. He realizes this is the eighth such bubble he’s inadvertently created, but dismisses them as harmless since they float so high in the sky.

Themes and Significance

“The Sky Trap” explores several key themes:

  • Unintended Consequences: Scientific experiments can have unforeseen and dangerous results
  • Accelerated Evolution: The story speculates about evolution proceeding at lightning speed under alien conditions
  • Human Civilization vs. Primitive Nature: The contrast between the characters’ civilized society and the primitive, chaotic life that emerges in the bubble
  • Leadership Under Pressure: Lawton’s emergence as a leader when traditional authority structures fail
  • The Fragility of Human Control: How quickly civilized behavior breaks down under extreme stress

The story serves as both an exciting adventure tale and a cautionary warning about scientific experimentation, showcasing Frank Belknap Long’s ability to blend cosmic horror elements with hard science fiction concepts. The invisible trap becomes a pressure cooker that reveals both the worst and best of human nature under extreme circumstances.

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