Set in the 1920s, the story opens when Soviet authorities discover the body of engineer Pyotr Garin, apparently murdered at an abandoned dacha near Leningrad. Clues point to his work on a powerful heat ray, a theory reinforced by strange discoveries at the crime scene. It quickly becomes clear that the real Garin has escaped overseas while his friend, disguised as him, was killed. The mystery deepens as a tremor of scientific ambition begins to run alongside the police inquiry, hinting at a weapon with world-changing implications.
To pursue the truth, the Soviet Academy of Sciences dispatches physicist Vasily Shelga to locate Garin and persuade him to return. Meanwhile, Garin has already completed his heat ray, a device capable of burning through objects at great distances. With this terrifying technology in hand, he hatches a grand plan to seize leadership on the global stage, proposing to drill into South America’s deep gold reserves. In need of funding, Garin wins the backing of American industrialist Rolling, who approaches the venture with a mix of skepticism and strategic interest.
Rolling’s doubts gradually give way as Garin maneuvers the deal to fruition. After outmaneuvering rival interests and pulling Rolling into a tightly woven alliance, Garin also wins over Rolling’s confidants, including Rolling’s lover, Zoya, whose involvement is pivotal to Garin’s financial foothold. With the money secured, Garin’s bold plan begins to take shape, and the heat ray’s potential for both progress and ruin becomes increasingly evident. Rolling’s own ambitions in the venture grow as he witnesses the device’s raw power, while Garin quietly calibrates how far he’s willing to push the envelope.
As word of Garin’s invention spreads, the heat ray attracts the attention of Nazi-aligned factions. The growing intrigue brings secret plots to steal the device to the fore, including the maneuverings of Sheffer, Rolling’s secretary, who becomes entangled in schemes that threaten Garin’s control over the weapon. The intrigue deepens when German industrialist Dietz presses Garin with negotiation demands, though not all players meet clean fates—the nephew Dietz sends is murdered in the shadows of this international gambit. Through it all, Shelga remains on Garin’s trail, eventually locating him but suffering grave injuries in an ambush.
Garin, ever the strategist, invites Shelga aboard his yacht and aims to sail with Rolling and [Sheffer] toward South America, hoping to secure the final pieces of his plan. Yet Shelga cannot sway Garin from his course, and the two intelligence worlds collide aboard a fragile voyage that tests loyalties, ideals, and the temptation of power. A dramatic confrontation on the water unfolds as Shelga’s warnings clash with Garin’s conviction and Rolling’s ambition, and the political agents circling the heat ray close in.
In the climactic sequence, a saboteur strike aboard the yacht sets off a chain of catastrophic events. The tension erupts as [Sheffer] orchestrates disaster to seize control, and Garin’s stubborn resolve pushes the weapon toward a final, irreversible act. The heat ray’s last, fateful use fractures the volcanic crater itself, unleashing a flood that engulfs the vessel and its occupants. The sea swallows all but one sailor, who staggers ashore to a desolate coastline strewn with the remnants of ambition and the remnants of lives altered by a single, terrifying invention.
