On Christmas Eve, the weather is unusually hot, and the whole city is shrouded in an inexplicable mystery. The power station, running at full load, is filled with crises, and the fire department is on high alert. The personal troubles of the firefighters add emotional conflicts to this 'hard battle'. He Yongsen (played by Nicholas Tse), You Bangchao (played by Shawn Yue), and Ye Zhihui (played by Andy On) are brothers who have shared life-and-death experiences for ten years, but now each carries their own burdens: He Yongsen, who is highly regarded, is transferred from the fire department and feels discontent; Ye Zhihui is adept at managing relationships and is the fastest to be promoted; You Bangchao is carefree and unburdened by personal matters but is facing a troubled marriage. The secrets of betrayal hidden among the three brothers further strain their relationship. Meanwhile, a super firefighter from the mainland, Hai Yang (played by Hu Jun), arrives for duty and encounters challenges from the 'veteran' Pei Zong (played by Simon Yam), while he himself has an unresolved issue. The crisis finally comes when the power station explodes into flames, plunging Hong Kong into unprecedented darkness. A group of people is trapped in the inferno, their lives hanging by a thread. The firefighters enter the pitch-black environment, fighting against the deadly smoke, needing to save lives while also dealing with brotherly conflicts, along with the higher-ups' conservative orders that emerge from time to time. Will it be a case of 'one life for another, saving one counts' or 'obeying orders and prioritizing the bigger picture'? This fire is not just about rescue but also serves as a redemption among brothers, clearing the smoke that blinds their hearts and minds.