Irene Kelly Michaela McManus is shattered when her daughter Anna Grace Van Dien is murdered by a restaurant cook named Neville Jeremy Holm. Grief drives Irene to chase vengeance across parallel universes using a universe-hopping machine that lets her jump from one reality to another. Each jump intensifies the burden she bears, but she pushes forward, determined to stop Neville before more lives are torn apart.
In one reality, Irene crosses paths with Mia Stella Marcus, a teenage runaway whom Neville intends to murder. Irene intervenes, saving Mia and sparking a cautious alliance between them. Irene sends Mia on her way, only to discover the teen has stolen her gun. Realizing she cannot abandon Mia, Irene tracks her down again, and the two teenagers form a fragile partnership aimed at stopping Neville once and for all.
A tense encounter at a gas station follows, as Neville walks into the shop and a gunfight erupts between him, Irene, and the clerk at the gas station London Garcia. The clerk is killed by Neville, a brutal reminder of how dangerous this mission is across realities. After the confrontation, Irene urges Mia to climb into her universe-hopping machine, and the pair arrive in a new universe where the clerk is still alive, offering another chance to intervene in Neville’s schemes.
Irene explains that she has spent years tracking Neville’s variants, but every hop drains the fuel core that powers the device. The latest journey leaves her with dwindling power, so she seeks a replacement part by negotiating with smugglers. The smugglers are led by Billie Taylor Misiak, who offers a refurbished part in exchange for Mia. Irene resists at first, but Billie’s calm negotiation and the prospect of keeping Mia safe help defuse the tension. In a tense escape, they fend off a trap, kill one of the smugglers, and seize the fuel core for themselves.
The trail leads them to another universe, where Irene reveals a grim truth: she is the only version of herself who didn’t die after Neville killed Anna, and she has been using her abandoned home as a temporary base between jumps. While Mia sleeps, Irene slips away to Neville’s home and discovers that he has murdered the Mia of that universe. The sight shakes Irene, but it also deepens her resolve. When she returns to Mia, the two have grown closer, and Mia urges a shift away from killing. Irene agrees to protect Mia, but the path ahead remains dangerous.
A turn of events pushes them toward a universe where Anna is alive and Neville’s hold on the past loosens. Irene travels to her own home only to find herself sharing it with a version of Anna who seems content. She reveals herself to Anna and says goodbye, a moment that underscores the personal costs of Irene’s mission and the complexity of the lives she has touched.
Meanwhile, Neville’s pursuit continues with brutal efficiency. Mia attempts to intervene, and as he is about to move the deceased Mia to his hideout, she fires a shot that clips him, but he overpowers Mia and drags both her and the dead Mia toward his lair. He places Mia in a barrel and tosses her into a lake, trapping her in the cold water. Irene arrives, and a lethal confrontation ensues as she shoots Neville. He recognizes Irene as the mother of a victim, and in a final, cruel twist, he hurls Irene into the lake after she becomes ensnared by a bear trap. As Irene sinks, Mia frees herself and delivers a final blow, killing Neville, and Irene surfaces, gasping but alive.
They return to the ruined home of Irene’s deceased self, where Irene sets the machine on fire. With the device burning, she and Mia sit side by side, and Mia rests her head on Irene’s shoulder, a quiet moment of connection born from shared loss and hard-won resolve. The smoke and embers mark the end of one perilous chapter and the uncertain promise of a new beginning for Irene and the teenager she has come to protect.
