Secret of the Earth Star

In Short

Henry Kuttner’s science fiction adventure novel follows three brothers—Tony, Phil, and Jimmy Martell—who become entangled in international espionage and jewel theft when the priceless Earth Star gem is stolen. To protect their father’s spotless honor, the brothers flee into the French Foreign Legion, only to descend into a subterranean labyrinth ruled by degenerate descendants of Atlantis. Facing monstrous artificial gods and a plot to destroy Europe, the brothers fight for survival in a forgotten subterranean world. Lasting as a prime example of mid-century pulp imagination, the novel endures through its relentless pacing, exotic atmosphere, and tragic fraternal bonds.

The Story

The story opens in an Indian palace where the legendary Earth Star—a supernally hard diamond-like gem born from an ancient tree-fern—is sold to a local ruler. The transaction is violently interrupted by the Merlin, a master thief who steals the jewel and escapes. In a New York penthouse, upright government official Seth Martell confronts his three sons, Tony, Phil, and Jimmy, demanding to know which of them is the outlaw. Although each brother independently claims to possess the stolen gem to protect the others, Tony is indeed the Merlin.

To shield their father from scandal, the brothers flee, enlisting in the French Foreign Legion at Azouad on the edge of the Sahara. Guided by hardened legionnaires like Captain Brady and the sun-allergic veteran Jacklyn, they descend into Sub-Sahara, an underground labyrinth. There, they discover that the indigenous Copts are in open revolt, manipulated by an ambitious commander named Desquer and an ancient Atlantean high priest named Thotmes.

Descending deeper into Alu, the forgotten subterranean metropolis of antiquity, the adventurers discover that Thotmes and his surviving Atlantean priests are using ancient science and healing rays to manufacture monstrous artificial gods—jackal-headed and crocodile-headed beings intended to terrify the surface world. Worse still, Thotmes plans to activate a catastrophic machine that will rip Europe from the Earth to form a second moon, drowning the continent in tidal waves while the priests retreat to sunken Atlantis.

Betrayals mount as Commander Desquer reveals his own ruthless ambitions. Trapped within the collapsing pyramid base of the machine, Phil is mortally wounded by Desquer. Driven to desperation, Tony and Jimmy use a carbon-pistol to shatter the massive machine and the pyramid supporting the cavern roof. The roof gives way, and the sunless Midnight Sea pours into Alu, unleashing a cataclysm of boiling lava and roaring floods that destroys the underground city and drowns Thotmes' empire.

Escaping back to the surface with Zadah, the Rajah’s vengeful secretary, Tony and Jimmy face one final confrontation in the desert. Jimmy is killed by Zadah before Tony eliminates the assassin. Flying back toward civilization over the Pacific, Tony buries Jimmy at sea, carrying the secret that Phil was the true Merlin. He returns to New York alone, leaving the stolen Earth Star behind and restoring his father’s honor at a bitter personal cost.

How It Unfolds

• The palace heist: The narrative opens with the shady sale of the Earth Star in India, abruptly shattered when the masked thief known as the Merlin steals the gem and escapes into the night.
• The penthouse interrogation: Seth Martell confronts his three sons in New York, forcing Tony, Phil, and Jimmy into a dangerous game of deception where each claims responsibility for the theft.
• Flight to the Legion: The brothers escape pursuing investigators via an amphibious plane and enlist in the French Foreign Legion at Azouad, plunging beneath the Sahara into Sub-Sahara.
• Descent into Alu: Guided through dark tunnels past Coptic uprisings, the group reaches Alu, a colossal pre-Egyptian metropolis preserved beneath a subterranean sea.
• The Atlantean plot: The adventurers uncover Thotmes and his priests breeding artificial animal-headed gods and plotting to destroy Europe with a machine designed to forge a new moon.
• Tragedy in the depths: Betrayed by Commander Desquer within the pyramid, Phil is fatally shot while trying to protect the secret of the gem.
• The final cataclysm: Tony and Jimmy trigger a catastrophic explosion that wrecks the machine, bringing down the cavern roof and flooding Alu with the Midnight Sea.
• A solitary return: After defeating Zadah in the desert and losing Jimmy to a final bullet, Tony flies back to New York alone, carrying the tragic truth of his brothers' sacrifice.

The People

• Tony Martell: The eldest brother and the true Merlin. Eager and sharp-minded, he bears the heavy burden of leadership and protects his family, ultimately surviving the ordeal alone.
• Phil Martell: The stocky, pipe-smoking middle brother. Loyal and fiercely independent, he matches his brothers' bluffs about the jewel before meeting a tragic end in the depths of Alu.
• Jimmy Martell: The youngest brother, whose boyish enthusiasm masks deep courage. He stands by his brothers through every peril until he falls victim to Zadah's betrayal in the desert.
• Seth Martell: Their father. A man of unswerving honesty and high military standing whose reputation serves as the moral anchor driving his sons' dangerous deception.
• Commander Desquer: A bull-strong, ruthless officer of the Legion. Driven by his own hidden motives, he uses the heroes for his expedition into Alu before turning violently on them.
• Thotmes: The ancient Atlantean high priest. Ruling the subterranean Copts through fear and genetic manipulation, he seeks to reshape the surface world by destroying Europe.

In Its Own Voice

On black velvet the great gem flamed.

This description introduces the supernatural wonder of the stolen Earth Star during the initial palace transaction.

The artificial monsters created by Thotmes and his servants roamed within the cage, men with the heads of teratological mythos.

Tony reflects on the horrifying biological creations imprisoned in the Atlantean pyramid.

Phil rested in the temple of Osiris—and Jimmy would lie beneath the waves that hid Atlantis.

Tony mourns his fallen brothers as he flies back toward civilization alone.

What It's Really About

The novel examines the weight of family loyalty against the rigid demands of personal honor and state duty. Kuttner explores how ancient mythologies—such as the Egyptian pantheon—are rooted in forgotten, highly advanced sciences that degenerated over millennia into crude superstition and tyranny. The story contrasts the corrupting allure of power, represented by the Atlantean priests and the cataclysmic Earth Star, with the selfless sacrifice of the Martell brothers. Ultimately, it questions what modern civilization owes to its prehistoric past and how far individuals should go to protect those they love from dishonor.

Why Read It Today

Readers who love fast-paced pulp adventure, lost-world tropes, and classic planetary romance will find much to enjoy here. Reading it feels like stepping into a breathless, imaginative serial where ancient history collides with high-tech science fiction. Kuttner keeps the momentum high, balancing grand underground vistas with genuine emotional stakes among the brothers.

Modern readers should note the period's limitations: the prose carries the breathless, melodramatic conventions of 1940s pulp magazines, and the background characters—particularly the indigenous Copts and Arab locals—reflect the casual Orientalism and dated racial attitudes common in mid-century adventure fiction. However, for those willing to look past these historical tropes, the tight pacing, inventive subterranean architecture, and the poignant emotional weight of Tony's solitary journey home make it a fascinating artifact of golden-age science fiction.