Andrew "Ender" Wiggin is a renowned tactician and Speaker for the Dead who lives on the planet Lusitania. Burdened by his youth, during which he was manipulated into committing xenocide against the Formic species, he now acts as a fierce protector of alien life. He serves as a central point of connection for the humans, the indigenous Pequeninos, and the secretly recovering Formic hive queen. His altruism drives him to shoulder heavy moral responsibilities for the survival of those around him.

Valentine is Ender's older sister, physically in her fifties but chronologically over three thousand years old due to the effects of relativistic space travel. She writes highly influential political treatises under the pseudonym Demosthenes. She journeys to Lusitania in an effort to use her political influence to stop the Starways Congress fleet from destroying the planet.

Jane is a sentient, intangible being who exists within the philotic twining between the ansibles, a galactic instantaneous communication network. Originally evolving from an interactive computer program connected to Ender's childhood thoughts, she possesses immense computational power and access to all digital data. She faces an existential threat from the Starways Congress, who plan to shut down the ansible network.

Miro is Novinha's oldest son, technically only twenty years old due to light-speed space travel, making him biologically younger than his siblings on Lusitania. He suffers from significant brain damage and physical disabilities after a traumatic encounter with a protective forcefield. He works as a xenologer, attempting to restore his complex relationships with his estranged family and the alien species he studies.

Novinha is a brilliant xenobiologist and the matriarch of the Rebeira family. She lives on Lusitania, working desperately to find a way to modify the deadly descolada virus so it will not harm other sentient species. Haunted by past traumas and the violent deaths of former partners, she maintains a strict, often controlling grip on her family dynamics and her scientific research.

Qing-jao is a highly intelligent resident of the planet Path, raised to strictly revere the gods. She is identified as "godspoken," a class of people who commune with the divine by performing agonizing purification rituals, such as obsessively tracing woodgrains in the floor. She receives an assignment from her father to investigate the mysterious disappearance of the Lusitania fleet, placing her in direct conflict with Jane's efforts.

Warmaker is a Pequenino fathertree who cultivates a dangerous, extremist religious movement. He preaches that the deadly descolada virus is an incarnation of the Holy Ghost and that the Pequeninos have a divine mandate to spread the infection across the universe, creating severe tension between the species on Lusitania.

Ela is one of Novinha's daughters, working alongside her as a highly skilled xenobiologist. She acts as a stabilizing force in her fractured family, often trying to find pragmatic, middle-ground solutions to the scientific and ethical disputes surrounding the descolada virus. She works to create a modified version of the virus that will protect both humans and the indigenous Pequeninos.

Grego is Novinha's youngest son, functioning as a physicist on Lusitania. He possesses an aggressive, hot-headed temperament and actively advocates for the total destruction of the descolada virus, regardless of its potential sentience. His confrontational nature frequently places him at odds with the more cautious members of his community.

Quara is the youngest daughter of Novinha and works as a xenobiologist. She holds a steadfast, contrarian belief that the descolada virus is an intelligent, communicative entity that possesses a right to live, comparing any attempt to alter it to performing a lobotomy. She frequently defies her family's wishes by sharing restricted research information.

Wang-mu is a brilliant girl born into the servant class on Path. Resentful of her low social standing and lack of educational opportunities, she maneuvers to become Qing-jao's secret maid in exchange for learning. Despite her inferior social status, she possesses sharp deductive skills and a strong sense of skepticism regarding the ruling Starways Congress.

Han Fei-tzu is a highly respected, godspoken man and a trusted advisor on the planet Path. He tasks his daughter, Qing-jao, with discovering the fate of the Lusitania fleet. While initially devout, his encounters with Jane and subsequent revelations about Starways Congress force him to reconsider the nature of his religion and the true cause of his people's purification rituals.

The Hive Queen is the last surviving member of the Formic species, secretly rebuilding her society in an underground city on Lusitania with Ender's help. She communicates telepathically with her drones and with select humans, attempting to understand human nature while building spacecraft to flee the incoming Starways Congress fleet.

Human is a Pequenino who has achieved his third life stage, existing as a sentient "fathertree." Rooted in place but capable of profound thought and communication, he frequently converses with the Hive Queen and Ender. He serves as a bridge of understanding between the indigenous Pequeninos and the human colonists.

Quim, who goes by the title Father Estevao, is a priest and one of Novinha's sons. He dedicates himself to the spiritual well-being of both humans and Pequeninos on Lusitania. Driven by compassion and religious duty, he sets out on a dangerous mission to reason with a group of Pequeninos who have adopted extremist, violent beliefs regarding the descolada virus.

Olhado is Novinha's son, easily distinguished by his mechanical eyes. He works as the manager of a brick factory and is a dedicated husband and father. He considers himself a passive, unbiased observer of his family's chaotic dynamics, looking up to Ender as a role model for fatherhood.

Jakt is Valentine Wiggin's husband, traveling alongside her across the galaxy. He provides emotional support for Valentine during their long space voyages and advocates for the rights and choices of the artificial intelligence Jane during tactical discussions with Miro.

Rooter is a Pequenino fathertree on Lusitania. He often engages in deep conversations with human religious leaders like Quim and serves as an elder figure among his species.

Ouanda is a xenologer on Lusitania and Miro's former romantic partner whose relationship ended due to painful family revelations. Now married with children of her own, she attempts to manage her lingering connection with Miro and her professional duties regarding the Pequeninos' intelligence.

Planter is a Pequenino who assists the human scientists in Milagre. Struggling with the revelation that his species' behavior might be entirely controlled by the descolada virus, he makes a profound, selfless choice to test whether his intelligence can survive without the biological agent.

Kovano is the mayor of Milagre on Lusitania. He attempts to manage the escalating political and physical threats on the planet, trying to balance scientific research with religious mandates while preventing the townspeople from devolving into violent mobs.

Bishop Peregrino is the highest religious authority for the humans in Milagre. He believes the church holds a responsibility toward Christians of all species, though his traditional mindset often clashes with the harsh realities of the alien biology and the escalating violence in his community.

Plikt is a family friend who travels through space with Valentine Wiggin and Jakt. She serves as a quiet, supportive presence during the intense philosophical and tactical discussions regarding Lusitania and the Starways Congress fleet.