Holsten is a classicist aboard the Gilgamesh who specializes in the languages and cultures of the fallen Old Empire. As an academic among military and scientific crewmembers, he brings a distinct perspective focused on history, empathy, and translation. He acts as a witness to humanity's desperate search for a new home and frequently advocates for diplomacy over aggression.

Portia represents a generational line of female jumping spiders on the Green Planet who evolve rapidly due to an Old Empire nanovirus. Throughout successive generations, individuals bearing the name Portia push the boundaries of their species, serving as hunters, explorers, warriors, and scientists. She functions as a straightforward, action-oriented leader who consistently works to ensure the survival and advancement of her civilization.

Dr. Avrana Kern is a highly accomplished scientist from the Old Empire who orchestrates an ambitious evolutionary experiment on a newly terraformed world. Driven by a desire to guide a new sentient species into the future, her extreme hubris leads her to view herself as a godlike creator. Following a catastrophic sabotage, she spends millennia in an orbiting pod, where her human consciousness slowly blends with the station's computer systems.

Bianca represents a generational line of physically powerful and intellectually ambitious female spiders. She frequently challenges the orthodoxies of her society, valuing scientific discovery and invention over religious tradition. Her iterations serve as warriors, scientists, generals, and inventors who pioneer new technologies and ways of interacting with the world.

Fabian represents a line of male spiders who demonstrate exceptional intelligence within a fiercely matriarchal society. As the species evolves, iterations of Fabian struggle against the biological imperatives that place males in constant mortal danger. He works as an ambassador, researcher, strategist, and advocate, leveraging his innovations to push for gender equality.

Isa Lain is the chief engineer of the ark ship Gilgamesh. Pragmatic, deeply dedicated, technically brilliant, and highly capable, she takes on the immense burden of keeping the decaying ship functional across millennia of travel. She serves as a stabilizing, protective force for the human survivors, prioritizing long-term survival and careful planning over conquest.

Vrie Guyen is the commander of the Gilgamesh, chosen for his exceptional ability to strategize and plan for the long term. Tasked with finding a new home for humanity, his immense responsibility gradually warps into a messianic complex. He relies on secrecy and manipulation, increasingly viewing himself as the sole savior of the human race at the cost of his crew's agency.

Karst serves as the chief security officer aboard the Gilgamesh. Relying heavily on military tactics and force, he represents humanity's violent and defensive instincts. He views unknown variables as immediate threats to be neutralized, frequently advocating for aggressive action when encountering alien environments or internal dissent.

Vitas is the chief science officer of the Gilgamesh. She adheres strictly to pure scientific observation, devoid of emotional or moral considerations. Her unwavering reliance on objective data makes her an efficient researcher but prevents her from exercising empathy or considering the sentience of non-human lifeforms they encounter.

Eliza is the Artificial Intelligence computer system operating Avrana Kern's orbiting Sentry Pod. Programmed to maintain the pod and assist the lead scientist, Eliza provides critical data and manages the station's automated defenses. Over vast spans of time, the AI's programming becomes fundamentally intertwined with Kern's isolated human consciousness.

Scoles is a colonist aboard the Gilgamesh who leads a violent uprising against Commander Guyen. Unwilling to be condemned to a freezing, desolate moon, he organizes a faction to seize control of shuttles in a desperate bid to land on Kern's World instead.

Nessel is a mutineer aboard the Gilgamesh who firmly believes that assigning colonists to a frozen wasteland is a cruel and unacceptable fate. Following a disastrous crash landing on the Green Planet, she is captured and studied by the evolving spider civilization.

Viola represents a line of spider scientists and lead warriors. She possesses a deep understanding of how her species transmits genetic memory from one generation to the next, playing a critical role in isolating the mechanics of immunity and unraveling the secrets of the nanovirus.

Sering is an agent of the extremist faction Non Ultra Natura (NUN), a group that vehemently opposes scientific attempts to exceed the limits of nature. He infiltrates Avrana Kern's facility to sabotage her evolutionary experiment, initiating a catastrophic explosion to preserve what he views as the natural order of the universe.