Black Coal, Thin Ice

Dismembered body parts are found scattered across coal factories in Heilongjiang Province, signaling a brutal murder case. An ID card recovered at a scene identifies the victim as Liang Zhijun, pulling detective Zhang Zili into the investigation. The case begins as Zhang is tasked with unraveling the mystery and tracing leads toward a suspect network linked to the coal industry.

The investigation traces to Liu Fayin, a coal truck driver. The pursuit takes Zhang to a beauty salon where the operation spirals out of control, drawing in officers and suspects. The raid ends with casualties and Zhang being shot, stalling the initial momentum of the case.

Five years pass since the raid, and Zhang has quit the police, sinking into alcoholism. On a stakeout, he encounters his former partner and learns that two more killings have occurred since the first, with victims found wearing ice skates and connected to Wu Zhizhen. He remains determined to pursue the truth despite his personal collapse.

Two more victims are found wearing ice skates and are linked to Liang Zhijun’s widow, Wu Zhizhen. Zhang watches Wu’s movements closely, sensing a larger conspiracy centered on her. The connection to Wu intensifies the ongoing investigation.

During a stakeout, Zhang’s bike is tampered with and Rong Rong’s true behavior comes into focus: she is sexually coercing Wu. Zhang tends to Wu’s injuries and helps manage the shop, while continuing to surveil Wu for more clues. The dynamic reveals the deeper manipulation behind the killings.

Zhang invites Wu on an ice-skating date. At the rink, Wu veers into a remote area and Zhang follows, knocking her down and kissing her. The moment blurs the line between protection and possession as danger closes in.

An undercover Captain Wang detects a truck tailing the couple and confronts the driver. The driver wears ice skates around his neck and is quickly cut down, signaling the killer’s ruthless reach. The pursuit intensifies as the case narrows toward Wu.

Zhang tracks the driver to his job as an ice-delivery man, using that position to conceal the remains of the first murder victim inside blocks of ice. He then witnesses the driver drop the ice blocks onto a coal train from an overhead bridge. The macabre method exposes the killer’s chilling efficiency.

Zhang forces the driver to reveal Liang Zhijun’s name and questions Wu, who confesses that Liang faked his own death to cover the original killing. Wu admits she was targeted and manipulated by Liang, revealing a deeper network of secrets. The confession reframes the case around Liang’s manipulation and Wu’s coerced role.

Using Wu as bait, Liang Zhijun makes a fatal appearance, and the police shoot him down. The physical threat is removed, but the moral and emotional threads of the case remain unsettled. Wu’s involvement remains a central, unresolved piece of the puzzle.

Forensics seek ashes from the first victim, but Wu claims she scattered them in the river. Zhang confronts Rong Rong again and pushes her to reveal the coat Wu damaged, which leads him to the Daylight Fireworks nightclub where the coat’s story echoes through the case. The investigation tightens around a crucial symbol: the coat and its missing owner.

Zhang invites Wu to an amusement-park date and they share a kiss on the ferris wheel, as the Daylight Fireworks sign glitters below. The moment heightens their bond even as the police close in on the truth. Wu is arrested the next day, and a drunken Zhang triggers fireworks in broad daylight, leaving the ending open and unresolved.