In Rome, a serial killer known as the Card Player uses a webcam setup to force the police into a live game of Internet poker, with a brutal fate awaiting the victim if the officers lose. The killings escalate quickly after a British tourist is murdered, prompting the authorities to assign John Brennan, an Irish policeman, to spearhead the case alongside Italian detective Anna Mari. The only clues tying the victims together are seeds found on their bodies, hinting at a meticulously planned pattern rather than random violence.
While canvassing an arcade, Brennan and Mari form an uneasy alliance and soon cross paths with Remo, a gifted young video poker aficionado who understands the game’s subtleties and the psychology of a killer who loves to stay one step ahead. Recognizing his talent, they recruit him to help them play against the Card Player, hoping his expertise can outmaneuver the mastermind behind the webcam plot. The stakes rise as the case deepens, and the team learns that nothing links the victims beyond the plant-based seeds that mark each crime scene.
The tension intensifies when Lucia, the chief of police’s daughter, becomes the killer’s latest kidnapping victim. The detective work shifts into high gear as Remo faces off against the killer in a dangerous online duel; he wins, and Lucia is eventually found alive in an alley, a fragile sliver of hope amid a growing sense of danger and urgency. The investigation also reveals a troubling romantic undertone: Brennan and Anna’s relationship has grown into something personal and powerful, driving them to push harder against a foe who seems to anticipate every move.
After a celebratory party for Lucia’s safe return, an alluring stranger lures Remo away, only to reveal herself as a pawn of the Card Player. The killer murders Remo with a boat hook, cutting off a crucial ally at a moment of fragile lull in the pursuit and leaving the team reeling from the double shock of loss and exposure.
As the pieces begin to fall into place, Brennan notices a crucial clue embedded in the first poker game—a cannon firing at noon each day. The timing indicates the recording was made three hours earlier, placing the Card Player’s lair near the cannon and providing a tangible link between the online game and the physical space behind the scenes. This discovery leads Brennan to the seeds’ source—the plant—and to the entrance of the Card Player’s room. When he finally pushes the door wide, a booby trap claims his life, delivering a devastating blow to the investigation and forcing Mari to carry the case forward in his absence.
With Brennan gone, Mari takes up the mantle and continues the pursuit with renewed resolve. A new chase unfolds when her coworker Carlo becomes a suspect, as seeds recovered from his car point to him as the killer. Carlo abducts Anna and handcuffs both her and Mari to a railroad track, forcing Mari to play for the key that could free them while a train bears down on them. Mari wins the first round, and she then leans on a trick from her father’s poker book to destabilize Carlo by mocking his confidence. Enraged, Carlo attacks, but Mari manages to seize the key and free one hand, enabling her to roll away just as the train approaches.
In the end, Carlo’s bluster proves to be his downfall, and he is killed when the train crashes through the scene. Some time later, Mari, now elevated to chief inspector, receives a phone call that she is pregnant—likely a result of the relationship that has blossomed with Brennan—and she answers with a quiet, knowing smile. The case closes with a sense of personal renewal amid the grim memories of the chase, leaving Mari to navigate both professional duties and a new chapter in her life.
