Ava Faulkner, a woman in recovery from addiction and a former soldier turned assassin, finds herself entangled in a dangerous game of survival. While in France, she captures an English businessman, hoping to uncover the motives behind the contract on his life. As fate would have it, another woman secretly listens in on their conversation, unaware of the risks that lie ahead.
Relocating to Boston after her mission, Ava reunites with her estranged family, including her sister Judy and hospitalized mother Bobbi, both of whom she hasn’t seen in eight years. Shortly after, her former Army superior and handler, Duke, dispatches her to Saudi Arabia for another assignment - taking out a German general. Cleverly, she lures him into a trap, administering poison designed to mimic a heart attack. Unfortunately, her plan is foiled by the general's security, leading to a violent standoff that claims the lives of all involved.
After the botched mission, Ava heads to Barneville-Carteret, where Duke apologizes for the misleading information that led to chaos. He suggests she take some time off, which brings her back to Boston. Here, she encounters her former fiancé, Michael, who is now dating her sister Judy. Tensions run high as old feelings resurface and unhealed wounds from the past threaten to erupt.
Across the ocean in British Columbia, Duke revisits his boss, Simon, who is keen on overseeing the safety of his daughter, Camille, who had been eavesdropping on Ava. Simon sees Ava as a risk due to her emotional detachment from the job and insists she must be eliminated. When Duke presses on how he perceives the threat posed by Ava, a deadly confrontation leads to Duke's demise at Simon's hands, with Ava discovering a video of the horrific event.
Back home, Ava is plagued by family complications; feeling the urgency to redeem herself, she offers to help Michael when he goes missing and is discovered in deep debt to a local gambler named Toni. After a fierce exchange of fists and threats with Toni's thugs, Ava strikes a bargaining deal to resolve Michael's debt.
In a chilling twist, Duke's fate weighs heavily on Ava, who confronts the menace that Simon represents. In a brutal showdown, they exchange blows, each sustaining serious injuries until Simon escapes under the veil of chaos that ensues from a fire alarm. Driven by vengeance, Ava finally corners Simon beneath the Zakim Bridge, ending his pursuit for good.
In a bittersweet moment of farewell, she advises Judy to leave the country and gives her the crucial account details to secure their future. Holding onto the last remnant of stability, Ava receives a letter from Duke expressing contentment with his life decisions. As she marches forward into an uncertain future, Ava realizes she may never truly escape the shadows, especially with Camille lurking in the background, a constant reminder of the past that refuses to let go.
