Iron Lung

Iron Lung Plot Summary

The Quiet Rapture

The distant future brings an inexplicable cosmic catastrophe known as the “Quiet Rapture.” Without warning, all stars and planets throughout the universe mysteriously vanish. Most of humanity’s population vanishes simultaneously, leaving only those aboard space stations and spaceships at the moment of the event.

The surviving remnants face impossible conditions. Without planets, there are no resources. Without stars, there is no light or energy. Survivors drift through absolute darkness, slowly consuming whatever supplies they possessed when the Rapture occurred.

The Mission

Simon is a convict imprisoned for his role in destroying a space station—an act that killed an unknown number of people. The survivors’ desperate situation creates opportunities for criminals. Simon receives an offer: pilot the SM-13 submarine, nicknamed the “Iron Lung,” on an exploratory mission to a mysterious moon, and earn his freedom upon completion.

The moon in question is covered entirely by an ocean of blood. The nature of this blood ocean—whose blood it is, how it formed, why it exists—remains unknown. The survivors need information about this anomaly, hoping it might provide clues about the Rapture or resources for survival.

The Iron Lung is a ramshackle vessel, barely functional. For safety reasons or due to the blood ocean’s properties, the submarine has been welded completely shut. Its porthole is sealed, preventing direct observation. Simon can only see outside by using a crude camera mounted to the exterior that captures still images rather than video. He operates essentially blind, navigating by instruments and occasional photographs.

Limited radio communications connect Simon to crew members stationed at the surface. These voices provide his only human contact during the dive into the blood ocean.

First Descent

Simon submerges into the blood ocean. The submarine’s sensors detect movement outside—something large is present. Simon captures camera images revealing a human skeleton on the ocean floor, suggesting previous human presence.

The surface crew retrieves the submarine to review findings. They order Simon to descend again and collect a sample from the remains. Simon, frustrated, demands immediate release. To get attention, he activates the camera.

The commander responds with fury. She explains the camera is actually an x-ray imaging device. Simon’s activation has exposed the surface crew to heavy radiation, potentially causing severe injury or death.

Deception Revealed

While operating the submarine, Simon discovers audio logs from a previous pilot. The logs prove the crew lied to him—he is not the Iron Lung’s first pilot as he was told. Previous missions occurred, and at least one other pilot operated this vessel. The deception raises questions about what happened to earlier pilots and what dangers the crew is concealing.

Simon attempts to inform the commander about an image he captured showing a living creature in the ocean. She dismisses his concern and urges him to focus on collecting the skeleton sample. Simon complies, navigating toward the remains.

As Simon progresses through the mission, disturbing phenomena occur. Blood begins dripping into the sealed submarine through unseen breaches. An unidentified liquid also leaks inside, mixing with the blood. When Simon finally collects the sample from the skeleton, something knocks him unconscious.

Deterioration

Simon awakens still inside the submarine. Camera pictures show evidence of movement around the vessel while he was unconscious. He assesses damage to the submarine and makes repairs, attempting to navigate back toward charted areas. However, Simon begins experiencing hallucinations and losing touch with reality. The isolation, radiation exposure, blood leakage, and unknown substances in the air are affecting his mental state.

Simon encounters the wreckage of another submarine labeled SM-8. He attempts to access data from its black box recorder but cannot retrieve the information. A woman’s voice speaks to him through the radio, describing a godly light existing beneath the blood ocean. Simon believes he is hallucinating this voice.

He experiences a vivid vision where the Iron Lung is destroyed. In this hallucination, Simon breaks through the ocean surface to witness a giant eye filling the entire stormy red sky above. He awakens again to find the vision was not real.

The commander contacts Simon, informing him he has been missing for several days—far longer than his oxygen supply should have sustained him. She orders him to recover data from the SM-8 wreckage, promising to personally rescue him if he complies. She reveals her name is Ava, offering this personal detail as a gesture of trust.

Meanwhile, conditions inside the Iron Lung continue deteriorating. Blood accumulates inside the vessel. Congealed organic matter collects on surfaces. Simon discovers his skin has become cracked and blistered, suggesting biological contamination or radiation damage.

Final Mission

Simon reaches the SM-8 wreckage and successfully accesses its black box data. The recovered audio logs contain a horrifying revelation: the blood ocean comprises human blood. The ocean is literally composed of human remains on an incomprehensible scale.

As Simon reviews this data, more blood and fleshy matter flood into the Iron Lung. The organic material is not just leaking in—it is growing inside the submarine, spreading like living tissue. Ava contacts Simon with devastating news: she cannot rescue him. The surface situation has become untenable. She apologizes but asks Simon to protect the SM-8 data at all costs, as it may save what remains of humanity.

Simultaneously, the mysterious woman’s voice speaks to Simon again, urging him to destroy the data to prevent others from learning about the light beneath the ocean. The conflicting instructions leave Simon torn between protecting humanity’s future and heeding the warning about forbidden knowledge.

A monster attacks Ava’s surface vessel, destroying it and presumably killing her. Simon is now completely alone, surrounded by blood and growing flesh both outside and inside the submarine.

Sacrifice

Simon struggles to move through the blood and fleshy material that has spread throughout the Iron Lung’s interior and begun growing on his own body. He makes a critical decision: the data must survive even if he cannot. Simon ties the SM-8 black box to a life vest designed to float on liquid surfaces.

He then deliberately sabotages the Iron Lung, compromising its hull integrity so it will fail catastrophically under the ocean’s pressure. The monster that destroyed Ava’s vessel attacks the submarine, biting into it with massive jaws. The combined stress from the monster’s attack and Simon’s sabotage causes the hull to implode violently.

The implosion kills both Simon and the monster simultaneously, destroying both biological threats in a single moment. The life vest containing the black box is shown floating on the surface of the blood ocean, intact and accessible. The data Simon died to protect has survived, potentially offering humanity’s remnants the information they need to understand their altered universe.