Rachel is an intelligent and highly capable intelligence analyst for the National Reconnaissance Office (NRO). As a "gister," she specializes in distilling complex data into concise, accurate summaries for government policymakers. She maintains a strained, distant relationship with her ambitious father and seeks to remain independent of his political maneuvers. Her analytical mind and commitment to the truth make her an ideal candidate for verifying a monumental scientific discovery in the Arctic.

William Pickering is the director of the National Reconnaissance Office (NRO) and Rachel Sexton's boss. Known as "the Quaker" for his quiet, unassuming demeanor, he operates a vast intelligence agency that works in complete secrecy. He is deeply protective of his agency and staff, expressing immediate suspicion regarding President Herney's motives for requesting Rachel's involvement in a classified matter.

Senator Sedgewick Sexton is a charismatic, silver-haired politician mounting a formidable presidential campaign against the incumbent. He capitalizes on public discontent with NASA, loudly condemning the space agency as a massive waste of taxpayer money. His public persona as a champion of fiscal responsibility masks a ruthless ambition and a willingness to use the people around him—including his own daughter—as political tools.

Michael Tolland is a celebrity oceanographer and the charismatic host of the popular television science program Amazing Seas. The White House recruits him to film a documentary about the newly discovered meteorite, hoping his mainstream credibility will legitimize the finding to the public. Behind his rugged and confident exterior, he carries the grief of losing his wife to illness, throwing himself entirely into his scientific pursuits.

Gabrielle Ashe is Senator Sexton's highly intelligent and ambitious personal assistant. She serves as a sharp political strategist, having engineered his campaign's successful attack on NASA's budget overruns. While she initially idolizes the senator and believes in his platform, her proximity to his ruthless tactics and questionable campaign financing forces her to reevaluate her loyalties.

Zachary Herney is the incumbent President of the United States, currently facing a difficult reelection battle due to his steadfast support for NASA. He is an affable and fundamentally decent leader with a genuine passion for space exploration. Hoping to secure his political future and restore public faith in the space agency, he leverages a monumental scientific discovery, calling upon independent experts to authenticate the findings.

The Delta Force team is a highly trained, elite military unit operating under a grant of complete presidential immunity. Led by an operative code-named Delta-One, the team utilizes cutting-edge, classified technology to monitor the scientists at the Arctic habisphere. They follow orders from a faceless controller with dispassionate precision and represent a lethal threat on the ice shelf.

Marjorie Tench is the senior adviser to President Herney and serves as the White House's chief political strategist. Known for her gaunt appearance and brilliant, calculating mind, she acts as the administration's enforcer. Tench is willing to employ aggressive, morally ambiguous tactics, including blackmail and media manipulation, to ensure the president's reelection and neutralize Senator Sexton's campaign.

Dr. Corky Marlinson is a brilliant but eccentric astrophysicist recruited by the White House to verify the NASA discovery. With a hyperactive personality and a tendency toward social awkwardness, he serves as an enthusiastic expositor of complex scientific data. He firmly believes in the authenticity of the meteorite and relies heavily on his established scientific knowledge.

Lawrence Ekstrom is the gruff Administrator of NASA. He fiercely protects the agency's reputation and deeply resents Rachel's presence at the Arctic site, viewing her both as a threat from the intelligence community and as the daughter of NASA's chief political enemy. He stakes his career and the agency's future on the successful announcement of the meteorite discovery.

Dr. Norah Mangor is a tough, brilliant glaciologist and one of the four civilian experts recruited by the president. She is fiercely protective of her own data and scientific methods, taking pride in her conclusion that the meteorite was sealed in pristine, ancient freshwater ice. She is pragmatic and strictly relies on empirical evidence.

Dr. Wailee Ming is a renowned paleontologist who forms part of the independent civilian verification team at the Arctic habisphere. He provides crucial context for the fossilized creatures found within the meteorite, concluding that the organisms align with theories of extraterrestrial origins. He is detail-oriented and dedicated to scientific observation.

Yolanda Cole is a seasoned news editor at ABC and a trusted friend to Gabrielle Ashe. She operates in the fast-paced world of national media and provides Gabrielle with pragmatic advice when the younger woman faces professional and personal crises. Yolanda understands the mechanics of political scandal and media spin.

Chris Harper is the mission director for NASA's Polar Orbiting Density Scanner (PODS) satellite program. He operates under extreme pressure from NASA leadership to present his project as a flawless success. His actions are heavily scrutinized by Senator Sexton's campaign as they search for evidence of NASA's incompetence and cover-ups.

Xavia is a marine geologist working aboard Michael Tolland's high-tech research vessel, the Goya. She remains on the ship while the rest of the crew goes ashore, analyzing geological data and providing Tolland with critical information regarding rock compositions and deep-sea geology.