Jeff Spender is an archaeologist on the Fourth Expedition. He deeply respects the vanished Martian culture and resents his fellow human crew members for their crass behavior. He reads Martian literature and studies the ruins, developing a philosophy that humans are an inherently destructive presence on the planet.

Captain Wilder commands the first truly successful human expedition to Mars. He acts as a moderate voice among his crew, attempting to balance the aggressive, uncultured tendencies of some men with the extreme, radicalized views of others. He respects Martian history but remains committed to his role as an explorer and leader.

Sam Parkhill is a member of the Fourth Expedition who approaches Mars as an opportunistic conqueror. He uses ancient Martian cities for target practice and later attempts to capitalize on the incoming human traffic by opening a hot dog stand on a dusty highway. He solves problems through violence and displays extreme prejudice toward the planet's original inhabitants.

Martian Tom is a surviving Martian who possesses telepathic and shape-shifting abilities. He enters human settlements and adopts the physical forms of lost loved ones. He acts out of a desperate desire for acceptance and belonging, though he struggles to control the illusions he projects when surrounded by multiple humans with conflicting desires.

Ylla is a Martian woman trapped in a monotonous marriage. Like many Martian women, she has telepathic abilities that manifest in the form of prophetic dreams. She begins dreaming vividly of an incoming Earth ship and its captain, singing strange songs in her sleep and anticipating his arrival.

Yll is a Martian man whose marriage has grown stale. When his wife begins talking in her sleep about a handsome man from Earth, his boredom rapidly transforms into intense, controlling jealousy. He takes deliberate steps to prevent her from meeting the subject of her dreams.

Captain Nathaniel York is the commander of the First Expedition to Mars. He serves primarily as an idealized figure in Ylla's prophetic dreams, representing the first intrusion of human consciousness onto the Martian planet.

Captain Williams commands the Second Expedition. He arrives expecting parades and accolades for humanity's monumental achievement of crossing space. Instead, he finds the locals entirely uninterested in his presence, treating him as a nuisance rather than an explorer.

Mrs. Ttt is a Martian resident who encounters the first wave of human explorers. She displays absolutely no interest in their arrival, focusing entirely on her baking and eventually forgetting they are even standing in her home.

Mr. Xxx is a Martian psychologist. When he examines the human crew of the Second Expedition, he concludes that they are simply Martians suffering from severe psychological delusions. He believes the humans' ship and crewmates are all incredibly detailed hallucinations.

Captain Black commands the Third Expedition. Upon landing, he is shocked to discover a town that perfectly mimics Green Bluff, Illinois, in the year 1926. Though deeply suspicious of the familiar surroundings, he is eventually swept up in the emotional pull of reuniting with deceased family members.

Hinkston is the archaeologist on the Third Expedition. Faced with an impossible Earth-like town on Mars, he tries to formulate scientific and historical theories to explain how humans might have settled the planet decades prior.

Lustig is the navigator for the Third Expedition. He is the first to completely abandon his caution when he spots what appear to be his deceased grandparents living happily in the strange Martian town.

Biggs is a boisterous crew member on the Fourth Expedition. He views the landing on Mars as an excuse to drink and party, showing zero respect for the ancient ruins. His crass behavior, which includes throwing bottles into canals, quickly angers the crew's archaeologist.

Hathaway is a physician and geologist on the Fourth Expedition. Decades later, after a massive war on Earth cuts off space travel, he remains on Mars living an isolated life with his family, eagerly awaiting a rescue rocket in the ruined landscape.

Tomás Gomez is a human settler traveling through the blue hills of Mars. He holds an optimistic, appreciative view of the planet, believing humans should not force Earth customs onto it. During his drive, he experiences a strange encounter with an indigenous being from another time.

Pop is an older settler running a gas station far from the main colonies. He moved to Mars specifically because it is entirely different from Earth, and he openly criticizes the settlers who spend all their time trying to recreate their old lives on the new planet.

Muhe Ca is a Martian who encounters a human on a night road. Through a distortion in time, he exists in a period where Martian cities are thriving, completely unable to see the human settlements that have supposedly replaced them.

Samuel Teece is a racist hardware store owner in the American South. Furious that the local Black community has built their own rockets to leave for Mars, he tries every tactic available—from intimidation to enforcing minor debts and labor contracts—to keep them under his control.

Silly is a young boy who works in Samuel Teece's hardware store. He is desperate to join his family on their rocket to Mars but finds himself momentarily trapped by an employment contract Teece holds over him.

Belter is a member of the migrating community who owes fifty dollars to a local hardware store owner. He is threatened with a horsewhip and forced off his horse until the community rallies to pay his debt.

Grandpa Quartermain is a local man observing the rockets leaving for Mars. When Teece attempts to legally trap a young boy from migrating, Quartermain diffuses the situation by volunteering to take the boy's place in the store.

William Stendhal is a wealthy man deeply aggrieved by the Great Fire, an Earth government purge that destroyed all imaginative literature. To protest laws that demand absolute realism, he builds a massive, mechanical house on Mars specifically modeled after the works of Edgar Allan Poe.

Mr. Garrett is an Investigator of Moral Climates. He represents the oppressive, censorious authorities of Earth who dictate that all art must be strictly realistic, arriving to ensure Stendhal's bizarre house is demolished by the Dismantlers.

Pikes is a former cinema special effects master whose career was destroyed by the government's ban on imaginative art. He works with Stendhal to populate the massive house with incredibly lifelike robots and elaborate mechanisms.

Mr. Bigelow is an architect hired to build a very specific, dark house on Mars. He is a product of his era, entirely ignorant of the classic literature that inspired the building he just completed.

LaFarge is an elderly man who traveled to Mars for retirement. He carries deep grief over the death of his fourteen-year-old son, Tom. When a being claiming to be Tom appears at his house, LaFarge recognizes the logical impossibility but allows his desire for a son to overrule his caution.

Anna is an elderly settler living on Mars. Unlike her husband, she refuses to question the miraculous reappearance of her dead son, choosing instead to fully immerse herself in the recreated domestic bliss of her past.

Elma is the wife of Sam Parkhill. While her husband builds a hot dog stand on Mars with grand dreams of wealth, she watches his efforts and his violent reactions to the local environment with a dry, pessimistic attitude.

Walter Gripp is a prospector who works far from the main settlements. When the majority of humans evacuate Mars, he finds himself alone. Desperate for companionship, he obsessively tracks down the source of a ringing telephone, hoping to find the perfect woman.

Genevieve Selsor is a human woman who specifically chose to stay on Mars when everyone else evacuated. She enjoys the freedom of the empty cities, eating what she wants and living exactly as she pleases without facing the harsh judgment of Earth society.

William Thomas is a survivor of Earth's destructive war. He brings his family to Mars under the guise of a vacation, intending to completely sever ties with the oppressive history and politics of Earth. He wishes to raise his children as the true inheritors of the Martian planet.

Timothy is a twelve-year-old boy whose family flees to Mars. Standing on the cusp of maturity, he recognizes that his parents are acting strangely and takes on the responsibility of treating their arrival as a game to keep his younger brothers calm.

Bert Edwards is a friend of the Thomas family. He is expected to arrive on Mars in a separate rocket with his wife and four daughters to help establish a completely new, post-Earth civilization.