Martha, portrayed by Anna Kendrick, finds herself in a shocking situation when her boyfriend unexpectedly enters her apartment while passionately entangled with another woman. As they try to persuade her into a threesome, Martha, feeling betrayed, decides to leave, remarking sarcastically that her boyfriend believes she has no sense of adventure, before retaliating by chucking an item at his head.
In parallel, we are introduced to the enigmatic hitman known as "Mr. Right," whose real name is Francis, masterfully played by Sam Rockwell. Assigned by a woman to eliminate her husband, Francis instead ends up killing her after collecting his fee. Outside, a team of agents led by the determined but somewhat clumsy Hopper, portrayed by Tim Roth, prepares to apprehend Francis. One by one, Francis manages to outsmart and eliminate the agents, showcasing his dangerous skills.
After the dramatic incident with her boyfriend, Martha takes refuge with her best friend Sophie, who is played by Katie Nehra. The two ladies engage in a night out, where Martha cannot shake off thoughts of her unfaithful boyfriend, leading to a conflict of emotions as Sophie attempts to encourage her to move on. To further distract Martha, Sophie suggests they adopt a pet. Martha chooses a seemingly ferocious cat, despite Sophie’s warnings, resulting in a playful yet painful scratch.
An unexpected twist occurs when Martha encounters Francis at a supermarket after accidentally knocking over some condoms. Initially coming off as a bit creepy, their interaction becomes less awkward as they end up spending an enjoyable day together. However, lurking behind the scenes are competing hitmen determined to hunt down Francis, though he always seems to be one step ahead, evading danger at every turn.
As the story unfolds, the plot thickens with the introduction of the Cartigan brothers, Von and Richie, brilliantly played by James Ransone and Anson Mount, respectively. Their dysfunctional relationship adds another layer of complexity to Francis’s life, with Von desperately seeking to eliminate Richie. Meanwhile, Hopper is revealed to be posing under another man's identity while still intent on taking out Francis.
In an unexpected turn during a date at a restaurant, Francis finds himself interrupted yet again by a hitman demanding his services. In an intense burst of action, Francis confronts and kills the man with a swift motion, casually returning to Martha and making a light-hearted comment that she initially perceives as a joke.
As their relationship grows, Martha's fascination with Francis also deepens, prompting her to engage in intense conversations about his past. One fateful day, while waiting at a scenic bridge, she witnesses Francis execute a hit right before her eyes, shattering any illusion she had about his profession being harmless.
Back at home, the tension escalates when Hopper arrives to warn Martha about the truth of Francis’s violent life. He explains Francis's moral code that dictates he only kills those he believes deserve it, and, intriguingly, that he even wears a clown nose during his jobs—information that causes Martha to reconsider her feelings.
Just when things seem to be settling, conflict erupts when Francis faces off against Hopper, dragging him into Sophie's apartment. The chemistry between Martha and Francis reignites, leading to an unexpected make-out session before chaos ensues as the Cartigan brothers send their men after him.
Martha finds herself kidnapped and taken to the Cartigan's hideout, where Francis courageously follows to rescue her. In an exhilarating showdown, he teams up with Shotgun Steve, portrayed by The RZA, to eliminate several mobsters. Choosing to step away from his violent lifestyle, Francis throws a gun between the feuding brothers, leading to a deadly confrontation.
The plot crescendos with Francis narrowly escaping a fatal encounter with Hopper, who meets his fate at the hands of Steve. As they attempt to embrace a life together, the couple faces ongoing threats from those still hunting Francis. In a thrilling twist at the end, during a seemingly casual date, Francis communicates with a lurking adversary, only to have Martha surprise him by taking the matters into her own hands, showcasing her newfound resolve as she executes a bold act of courage.
