Shannon Moss is a special agent for a clandestine division of the Naval Criminal Investigative Service (NCIS). Bearing a prosthetic C-Leg due to a severe injury sustained during training, she travels through time and space to inadmissible future trajectories to solve crimes. Driven by a traumatic past involving her childhood best friend, Moss is methodical and fiercely determined to impose order on a chaotic universe.

Karl Hyldekrugger is a charismatic former doctoral student specializing in Viking mythology who serves as a celestial navigator aboard the USS Libra. He espouses an apocalyptic worldview heavily influenced by Norse myth, specifically the concept of Ragnarök. Known by the nickname "the Devil" among his followers, he acts as a ruthless leader who manipulates the fears and traumas of others to build a loyal, fanatical network.

Philip Nestor is an FBI Special Agent who assists Moss with the Mursult family homicide investigation. He is a sensitive, empathetic investigator whose compassionate nature contrasts with Moss's hardened pragmatism. Across different possible futures, his life takes drastically different paths, ranging from a reclusive dealer of military memorabilia to a high-ranking bureau official.

Nicole Onyongo is a world-weary nurse battling addiction who becomes deeply entangled in the fallout of the USS Libra's mission. She carries the heavy burden of surviving intense violence and domestic abuse. As Moss investigates the Mursult case by adopting a cover identity in an alternate timeline, Nicole becomes a crucial source of information and a complex friend.

William Brock is the FBI Special Agent in Charge assigned to the Mursult family murders. He is a tough, dedicated professional and a devoted family man who quickly adapts to the bizarre realities of the Naval Space Command's top-secret time-travel programs. His character demonstrates a core decency, showing genuine concern for his colleagues while aggressively pursuing justice.

Patrick Mursult is a Navy SEAL and crew member of the lost ship USS Libra whose sudden reappearance triggers a massive investigation. Officially listed as Missing in Action, he becomes the primary suspect when his family is brutally murdered. He is a morally complicated figure whose desperate actions are motivated by grief and a desire to escape his tragic reality.

Charles Cobb is a physically imposing Navy SEAL and former crewman aboard the USS Libra. He functions as a brutal enforcer for Karl Hyldekrugger's fanatical network. Unwavering in his loyalty, he relies on violence and intimidation to protect the group's secrets and carry out its objectives against military and government targets.

Jared Bietak is a machinist's mate who served on the USS Libra and maintains the damaged vessel. He is a loyal follower of Karl Hyldekrugger and a volatile, abusive husband. His actions and allegiances help form the violent foundation of the extremist network Moss is attempting to dismantle.

Elric Fleece is a former electrician on the USS Libra who lives on a remote, squalid property in West Virginia. Deeply disturbed by his experiences, he creates macabre art from animal bones and wire, reflecting a fractured mind. His disturbing actions tie directly into the kidnapping at the center of the 1997 homicide investigation.

Elizabeth Remarque is the highly principled and brilliant commander of the USS Libra. Faced with an incomprehensible cosmic threat, she advocates for extreme self-sacrifice to protect the rest of humanity. Her rigid moral stance creates severe friction among her crew, sparking a violent mutiny.

Marian Mursult is Patrick's 17-year-old daughter whose disappearance drives the initial criminal investigation. She bears a striking physical resemblance to Moss's deceased childhood friend, creating a deep emotional resonance for the investigator. Thrust into a nightmare, Marian endures severe trauma as she is caught in a conspiracy involving time travel and biological weapons.

Vivian Lincoln is an ambitious woman who initially encounters Moss as a young hotel clerk before being inspired to join the FBI. In various timelines, she operates as a highly capable undercover agent attempting to infiltrate a dangerous domestic terror network. She bravely works through perilous situations, using relationships with dangerous men to gather intelligence.

Courtney Gimm is Moss's childhood best friend whose unsolved murder during their teenage years profoundly shaped Moss's life trajectory. Though deceased in the primary timeline, Courtney's memory hangs over the narrative. Moss frequently uses her late friend's name as an alias during undercover operations, keeping Courtney's presence active throughout the investigation.

O'Connor is Moss's pragmatic supervisor and the person who originally recruited her into the secretive division of NCIS. He manages the complex logistics of investigating crimes that span multiple timelines and futures. He acts as a stabilizing authority figure, issuing orders and providing crucial context regarding the top-secret Deep Waters program.

Dr. Wally Njoku is an elderly, philosophical physicist stationed at Naval Air Station Oceana in a future timeline. He provides Moss with cover identities, historical context, and scientific explanations regarding the mechanics of time travel and alternate realities. He views the branching timelines with calm resignation, seeing all possible lives as existing simultaneously.

Ryan Wrigley Torgersen is an FBI employee who becomes tragically involved in a domestic terrorism plot. He is targeted by an extremist group that utilizes psychological warfare and temporal manipulation to coerce him into carrying out devastating attacks against government facilities.

Dr. Peter Driscoll is a brilliant scientist and founder of the tech company Phasal Systems. He utilizes future technology to develop advanced medical treatments and create sophisticated AI simulations. His research makes him a prime target for those attempting to manipulate the timeline, drawing the FBI and Moss into his orbit.

Carla Durr is a lawyer from Canonsburg who represents Patrick Mursult. Her involvement in his case inadvertently connects her to top-secret naval intelligence and a sprawling conspiracy. She becomes a high-value target for assassins seeking to prevent the dissemination of classified information regarding extraterrestrial discoveries.

Amanda Moss is Shannon's mother, a resilient woman dealing with severe health issues. In alternate timelines, she is a beneficiary of experimental nanotechnology treatments for cancer. Her condition provides Shannon with personal stakes in the futuristic technology she encounters during her missions.

Davy Gimm is Courtney's brother who enlists in the military. He rents out his family's former home on Cricketwood Court to Patrick Mursult, inadvertently tying his family's past to the present homicide investigation.

Miss Ashleigh is Jared Bietak's mother and Nicole's mother-in-law. She resides on a property in Buckhannon, West Virginia, that serves as a front for her son's extremist activities and chemical weapons operations.

Admiral Annesley is a high-ranking naval officer interested in acquiring classified intelligence regarding the lost ship USS Libra and its discoveries. His pursuit of this information sets into motion catastrophic events for the Naval Space Command.

Egan is an FBI agent operating in a future timeline alongside his partner Zwerger. He assists undercover agent Vivian Lincoln in extracting targets from dangerous situations, acting as backup against highly organized extremists.

Zwerger is an FBI agent who works with his partner Egan in an alternate future. He is part of an extraction team tasked with securing individuals linked to a dangerous terrorist cell, supporting undercover operatives in the field.

Richard Harrier is a hitman employed by Karl Hyldekrugger. He becomes romantically involved with an undercover FBI agent who uses him to gain deeper access into the terror network.