Joseph Smith, portrayed by Jason Statham, is a former Special Forces veteran who has gone AWOL from his unit in Afghanistan. Now, he finds himself living as a homeless drunk on the streets of London, grappling with his circumstances. In a desperate attempt to evade thugs, he breaks into an apartment belonging to a man named Damon, who happens to be away for months. Embracing this new identity, Joseph starts to call himself Joey Jones. Amidst this turmoil, he is driven by the need to locate Isabel, a woman he was ripped away from while hustling on the streets.
Joey's discovery of a credit card amidst the apartment's mail sparks his journey toward self-improvement. He strikes up a friendship with Cristina, a kind-hearted nun portrayed by Agata Buzek, who operates a soup kitchen. Cristina helps Joey not only with basic needs like medicine but also connects him with messages about Isabel. Demonstrating his impressive fighting skills, Joey is recruited by Mr. Choy, the owner of a Chinese restaurant, where he takes on the role of a driver and enforcer, collecting extortion payments and delivering illicit goods. As he earns money, Joey begins to share his newfound fortune by ordering pizzas for the soup kitchen and supporting Cristina, earning a reputation among the homeless as "Crazy Joe."
His past soon resurfaces when he reconnects with his ex, Dawn (Vicky McClure), gifting her money and fabricating a tale about being Damon's boyfriend to the neighbors. During a dinner invitation extended to Cristina, an unplanned barbecue session leads to a heart-wrenching moment—Cristina reveals a police photo of Isabel, who has been tragically murdered. Filled with rage, Joey lashes out, but Cristina’s comforting words guide him towards a path of honesty and healing.
Joey's commitment to uncover the truth about Isabel's death intensifies. As he tracks down the perpetrators responsible for her murder, he shares an intimate evening with Cristina at an art gallery, divulging the information he has. A budding romance between these two blossoms, punctuated by Cristina's upcoming ballet ticket for October 1st, which coincides with Damon's return.
As the police delve deeper into Joey's dubious activities, Cristina finds herself entangled in the investigation. Vulnerably, she unveils her troubled past to Joey—she had endured trauma at the hands of her gymnastics instructor in Warsaw, whom she ultimately killed. Overcome with shame regarding their growing relationship, Cristina seeks reassignment to a different mission in Sierra Leone, but Joey remains determined to find justice for Isabel.
In a gripping twist, Joey learns of Isabel's murderer, Max Forrester (Christian Brassington), through an unexpected invitation to a rooftop cocktail party. This fateful event occurs on the same day of Cristina’s ballet. On the fateful October 1st, Joey steals a moment with Cristina, asking her to capture photos of him for his daughter, while foreshadowing his impending transformation with Damon's return imminent. Faced with the ultimate decision between love and vengeance, Joey chooses to confront his past.
In a climactic confrontation, Joey meets Max at the party and hurls him off the roof. Meanwhile, Cristina, unaware of his actions, leaves the ballet in search of him, eventually finding Joey in a vulnerable state on the curb, intoxicated and regretful. As the story unfolds, the following day brings Cristina's departure for Africa along with a note from Joey, signaling his return to homelessness.
As the police close in, Joey walks the streets once more, wrestling with his choices and their consequences, as he reflects on the life he once knew.
