Solaris, a mysterious planet orbiting a binary star system, is shrouded by an enigmatic ocean. This ocean, a peculiar colloid, morphs to keep the planet's path stable, preventing it from succumbing to the gravitational pull of its twin suns. Discovered by Earth explorers a century before the events of the novel, Solaris and its singular inhabitant, the ocean, have captivated scientists, giving rise to a dedicated field of study and a vast compendium of research.

Arrival at the Station

Young researcher Kris Kelvin arrives at a floating laboratory positioned above the Solarian ocean. The station, meant to house three other scientists, is in disarray. Kelvin soon learns that Gibarian, one of the scientists, has recently died by suicide. Another, Sartorius, remains secluded in his quarters, while Snow, the third, greets Kelvin with palpable fear, requiring proof of Kelvin's identity before allowing him in.

Unraveling the Mystery

Alone, Kelvin feels an unsettling sense of being watched. Thus begins his journey into unraveling the mystery that has disrupted the research station. As he investigates, he discovers the ocean's astonishing ability to probe the human mind, conjuring physical manifestations of people from the scientists' pasts.

The Ocean's Projections

These manifestations, called "Phi-creatures," include Gibarian's visitor—a giant African woman who haunts Kelvin's mind as he finds her beside Gibarian's remains. Sartorius, meanwhile, locks himself away, accompanied by the laughter of a child, while Snow's visitor remains an enigmatic presence, unseen by Kelvin but always near.

Confronting Personal Fears

Initially, Kelvin worries he might be losing his grasp on reality. Yet, after verifying his observations against lab data, he reluctantly accepts his sanity. His own visitor soon appears—a woman resembling Rheya, his wife who had taken her own life a decade ago. Despite her conviction, she is not truly Rheya. Kelvin resorts to deceiving her into a shuttle, expelling her into space, only for a second Rheya to appear, a relentless reminder of the ocean's creations.

Understanding the Phi-Creatures

Kelvin examines this second Rheya, discovering her body is constructed not from traditional atoms but from subatomic particles. Acknowledging she is not genuinely his wife, he nonetheless becomes deeply attached to her, even as he doubts whether these beings can exist beyond Solaris.

A Plan for Resolution

Snow and Sartorius devise a strategy to eliminate the visitors, theorizing they stem from subconscious thoughts during sleep. By transmitting a person’s conscious brainwaves—their encephalogram—to the ocean, they hope to neutralize these creations. Kelvin consents to provide his own encephalogram for the experiment.

The Deception Unravels

Rheya, disturbed by a recording of Gibarian's reflections, makes a drastic attempt to end her own life but recovers swiftly. Though both she and Kelvin recognize she is not truly Rheya, Kelvin maintains the pretense, claiming her humanity in an attempt to offer her solace. He resolves to stay with her indefinitely at the station.

The Final Goodbye

Rheya seeks confirmation from Snow but, upon receiving none, persuades him to use the "destabilizer"—a device he and Sartorius have perfected—to end her existence. Stricken by her loss, Kelvin proposes to Snow that they recommend the ocean's destruction to Earth's council, but Snow, driven by the quest for understanding alien intelligence, declines.

Acceptance and Hope

Determined to comprehend the ocean, Kelvin ventures to a makeshift beach forged by the ocean's whim. He reaches into the waves, which envelop but do not touch him. Realizing genuine communication with the ocean is unattainable and that Rheya will not return, Kelvin is overcome with despair. Yet, he resolves to remain on Solaris, driven by a faint hope and the belief that the era of miraculous events has not yet concluded.