The appearance of the White Hole triggers a global winter and mass deaths by suicide—copycats of Heaven’s Gate. At Naval Air Station Oceana, Operation Saigon—a mass evacuation of Earth—is underway, but Moss is determined to stay where she is, protecting the innocent to the end. O’Connor gives Moss a final assignment: investigate the shuttle Onyx, whose B-L fired at 10:53 Eastern—the exact moment the White Hole appeared—and from which Black Vale received an emergency beacon. Onboard, Moss finds the naked bodies of a mixed group of civilians, military, and political figures, including Senator C.C. Charley, Dr. Peter Driscoll, Admiral Annesley, and Carla Durr. All 20 passengers are dead, having brutally killed one another with handmade weapons. Moss realizes with horror that all the passengers are connected, forming a chain—the chain to the Terminus that Hyldekrugger sought to break. In saving Durr, Moss had preserved the chain—Durr was alive to sell Mursult’s secrets to Admiral Annesley, enabling the Onyx’s mission and bringing the Terminus to Earth. She grapples with the fact that each move in her career has brought the Terminus closer and closer. Horrified, she reflects, “I ended the world” (350).

In Durr’s belongings, Moss finds a letter from Mursult detailing the locations of Esperance and the ship Libra, describing Hyldekrugger’s actions and Mursult’s plan to escape into an alternate timeline to find a living version of his family. He notes that Hyldekrugger’s group marked each path with a cairn. Moss tries to contact O’Connor but can’t get through. She finds a video tape of Senator Charley who describes the discovery of “a planet rich in wondrous, strange materials, beautiful flora and undreamed-of life” (355). The video shows aerial footage of Esperance. 

O’Connor breaks through on the ship’s comm. He orders Moss to abandon the investigation and join the evacuation ship Cancer, but she disobeys. Moss manually overrides the Onyx’s instructions, and orders it to continue home to Oceana, defying O’Connor’s instructions not to come back. Moss remembers Mursult’s insistence in his letter that he would return to a time when Marian was just a child—he believed could travel back in time, not just forward. She realizes that her life in 1997 is not terra firma, but another IFT. She reasons that if Libra can be destroyed in a cascade failure, this entire IFT will blink and Esperance will go undiscovered—reducing, though not eliminating, the chance of the Terminus—and reality will reset to the date of Libra’s original launch, November 7, 1985—the true terra firma. After landing the Onyx at a chaotic Apollo Soucek, Moss is pulled from the cockpit by a desperate mob. She escapes in her truck and drives into the West Virginia forest, passing catatonic people with silver in their mouths and packs of “running men […] a group of thirty or so runners, nude and barefoot despite the freezing winds” (361). In the thin space, she falls into a freezing river but manages to pull herself onto the fallen Vardogger tree.

Near death from hypothermia, Moss finds the body of a woman in orange—the woman she remembers seeing before she was rescued from the Terminus—dead from QTN radiation. Raising the woman’s visor, Moss finds a version of herself, 20 years younger. She takes her corpse’s space suit, realizing that when her crucified body had been rescued by the Naval lander, that version of herself had been “pulled into this woman’s life” (368) and taken back to 1997. Following a path of burning Vardogger trees, she passes a dying Hyldekrugger and his catatonic followers before boarding the USS Libra, which is caught in a time loop. Moss’s suit catches fire and she panics that she will be stuck in the ship’s loop, burning forever. She enters zero gravity, signaling she’s officially entered the loop, just as the ship’s system puts out the fire on her suit. She arrives after the mutiny has begun and finds the ship’s bull nuke—the crew member in charge of the ship’s nuclear reactor—had been killed for trying to initiate the cascade failure on Remarque’s orders.

Moss finds young Nicole hiding from the mutiny and convinces her to lead her to Remarque, desperate to find the ship’s commander before Hyldekrugger’s men kill her. A firefight ensues, and Moss is shot multiple times—including in her shoulder, chest, and thigh—while killing two mutineers, Cobb and Fleece. The wounded Moss reaches the wardroom, where Remarque and her weapons officer, Chloe Krauss, have barricaded themselves. Their path to the engine room is blocked by Mursult, but Moss convinces him to let them pass by revealing the future fate of his family. After letting them through, gunfire erupts in the passageway behind them. In the engine room, Remarque announces the cascade failure is initiated, but Hyldekrugger and his men breach the door, killing Krauss and wounding Nicole. Hyldekrugger executes Remarque—yet the cascade failure succeeds. A black hole forms from the engine, consuming Moss, the ship, the Terminus, and the entire timeline.

On January 28, 1986, a teenage girl walks through the snow with her friend, Courtney Gimm, who is alive. At a convenience store, Courtney shows the woman behind the counter the jagged scar on her throat, attributed only to “some fuck lunatic.” The narrator buys a pregnancy test, which later confirms she is pregnant. In the middle of the night, she looks outside and sees a perfect, unexplained circle of footsteps in the fresh snow. She daydreams about her future with Courtney’s brother, Davy, and how they will marry before he joins the Navy. She imagines him at sea, looking up at a star he has picked out and named for her in her daydream—revealing the narrator is a young Shannon Moss in a new, reset timeline.