As Michael McCrea (Cillian Murphy) awakens, he finds himself confronted by two imposing figures: Ivan (Michael McElhatton) and Orlando (Don Wycherley). Their grim faces serve as a reminder of the serious debts he owes to Darren Perrier (Brendan Gleeson), a merciless crime lord. The thugs inform Michael that he must repay a significant sum by nightfall, or he will suffer inevitable consequences at their hands. With time running out, Michael reluctantly stirs from his slumber, seeking refuge in the comforts of home.
Downstairs, he comes face to face with Brenda (Jodie Whittaker), whose smile beams brightly as she receives a bouquet of flowers from her boyfriend, Shamie ([Pádraic Delaney]). Despite her attempts to engage him in conversation, Michael's thoughts are clouded by his raging financial concerns. In a state of desperation, he sets out to find a way to pay off his debt, turning to The Mutt ([Liam Cunningham]), a notorious loan shark known for his brutal methods.
At Delgado's Pool Hall, Michael's friend Clifford (Domhnall Gleeson) fills him in on the latest happenings: The Mutt has been banned from the establishment following a violent incident. Undeterred, Michael ventures out into the night, only to cross paths with two ruthless clampers, who promise to immobilize his car.
In the midst of his turmoil, Michael's estranged father, Jim McCrea ([Jim Broadbent]), unexpectedly shows up at his door, burdened with terminal cancer. Their strained relationship momentarily softens during a heartfelt encounter, but it’s cut short when Michael receives a tip about The Mutt's whereabouts and leaves his ailing father behind in search of financial reprisal.
Chasing down The Mutt leads Michael to a seedy pub, where he sees Shamie with another woman, stoking his anger. Michael delivers an ultimatum: Shamie must respect Brenda or face dire consequences. After a failed request for a loan from The Mutt, Michael begins to drink, transforming a bad night into a worse one when Shamie attacks him. With pride at stake, Michael counterattacks and demands Shamie end his relationship with Brenda once and for all.
As the night spirals into chaos, The Mutt reappears offering Michael a chance to join him and Dinny ([Breffni McKenna]) for a burglary job, tempting him with the potential for financial rescue. As they carry out their plan meticulously, they uncover incriminating evidence against their target. However, Michael's night takes a turn for the worse as he finds his car clamped, leading to a dangerous chase with Ivan and Orlando.
Abandoning his vehicle, he desperately makes his way home to retrieve a gun, only to find Brenda has taken it, grappling with the emotional turmoil of being cast aside by Shamie. Just then, Ivan and Orlando arrive, setting the stage for a violent confrontation. Luckily, Brenda intervenes, fatally shooting Orlando while Michael grapples with the aftermath of their chaotic predicament.
In a desperate attempt to cover their tracks, the trio takes Orlando's body to a remote location under the cover of night. After a harrowing experience stuck in a flooded car while Jim watches the chaos unfold, Michael and Brenda find themselves in precarious circumstances with a manhunt initiated by Perrier, who is enraged by Orlando's death and places a bounty on their heads.
As the troubles deepen, Jim reveals a shocking secret about his health, setting off a chain of events that leads to further peril. The gripping narrative unfolds against the backdrop of Michael's thoughts about family, betrayal, and survival, contrasting his past mistakes against his immediate need to resolve his financial and emotional dilemmas.
As Michael confronts Perrier's gang, tensions reach a breaking point. With secrets revealed and betrayals thrust into the light, the stakes are ever-higher as they engage in a deadly standoff, leaving Michael to confront not only his enemies but his own dark past. What follows is a whirlwind of gunfire, rage, and heart-wrenching losses that reshape his understanding of love, duty, and sacrifice.
In the somber aftermath, as Michael reflects at his father's funeral alongside Brenda, they find a semblance of peace amidst the chaos of their lives. The story culminates in a poignant moment, as Michael reaches out to Brenda, the weight of their experiences forging an unbreakable bond. As they embark towards a new chapter, the specter of their turbulent past lingers—a reminder of the transformative power of experience and the unpredictable journey that lies ahead.
