In a Madrid meeting of the Central Committee of Spain's Communist Party, a sudden blackout plunges the room into darkness, and when the lights come back, the Secretary General Fernando Garrido lies dead from a stabbing. The government tasks the anti-communist hard-nose Fonseca with uncovering the killer, while Santos, the interim head of the party, brings in a private investigator to take on the case. Enter the wry, sharp-witted detective Pepe Carvalho, arriving from Barcelona to pursue a trail that seems at once political and personal. Alongside him, Carmela, a militant communist, steps into the story as his driver and assistant, a partnership born from necessity and sharpened by curiosity.
From their first uneasy exchanges, it’s clear that Carvalho and Fonseca despise each other: Fonseca once hunted leftists like Carvalho, and the scars of that era color every move they make. Their parallel investigations weave a tense cat-and-mouse duet as they probe the corridors of power and the shadows beyond them. Carvalho’s path leads him to a former CIA chief, a veteran who now lives a crippled life in a wheelchair after injuries sustained in Vietnam; the old operative refuses to cooperate, tightening the sense that the truth is closely guarded by forces far larger than a single murder.
With the pent-up motive of the room, the suspects rapidly condense into a handful of possible betrayers within the Communist Party. The five who rise as the most plausible culprits are Sepúlveda , Esparza Julvé , Pérez Montesa , Leveder and Ordoñez. Both Carvalho and Fonseca scrutinize them in turn, peeling back layers of loyalty, money, and fear. Ordoñez, the eldest, is dismissed quickly by both investigators, and Leveder’s trail seems to vanish into a political crowd; yet the hunt intensifies as a public reading brings Carvalho face-to-face with new temptations and dangers.
A seduction becomes a trap: while tailing Leveder to a public forum, Carvalho is drawn into a flirtation with a journalist, a ploy that ends with him drugged and beaten by CIA agents intent on extracting what he’s learned. When he returns to his hotel room, a central European female agent—working for the KGB—awaits him, a reminder that his inquiry has drawn international interest and risk, and that he remains a target no matter how clever he thinks he is.
The investigation darkens with a key theory from Sepúlveda: the killer may have exploited Garrido’s cigarette smoke to find him in the dark. Yet Santos confirms Garrido was not smoking at the time, a clue that redirects Carvalho’s attention to the insignia of a harmonica on Garrido’s lapel—the visual beacon that allowed the killer to pinpoint his target in the blackout. This thread tightens as Carvalho discovers that Esparza Julvé—once a protegé of Garrido and Santos—has fallen on hard times. During a trip to Germany, he was approached by CIA operatives who hired him to kill the party leader for money. The truth surfaces in a brutal moment: Carvalho forces Esparza Julvé to reveal what he knows by seizing him at the point of a gun and pushing him into the traffic below, the killer whispering the name of his employer to Carvalho as he swallows the last of his fear.
Throughout the investigation, Carvalho has been dancing around Carmela, and she finally invites him to her apartment—their bond growing stronger even as danger closes in. Her husband and son are away, and a moment of intimacy seems at hand, but the delicate pause is broken by the appearance of the KGB agent, who hammers Carvalho with questions about his findings. Just as Carmela’s husband returns and the tension peaks, the web tightens: Esparza Julvé is unmasked as Garrido’s killer.
In a final confrontation at a new Central Committee gathering, Esparza Julvé is cast aside by those who now know his culpability. He tries to escape the building, but is felled by those who hired him, his fate sealed in a final, lethal act. With the mission accomplished, Carvalho departs for the airport, Carmela at the wheel, carrying him away as the case closes and the political landscape keeps moving forward, leaving the door to further conspiracies ajar for the future.