In 1943, the Jinchaji Border Area was deeply entrenched in the darkest moment of the Japanese army's summer sweep, during which the Japanese even used poison gas bombs. The Eighth Route Army urgently needed heavy firepower to break the deadlock. Just at that time, a 250-kilogram unexploded Japanese aerial bomb was found lodged in the soft mud at the base, caught the attention of the demolition expert Ning Yachuan, known as the 'madman.' Despite the fear of those around him, he not only successfully dismantled this 'iron watermelon' but also modified it into a powerful timed bomb, targeting the heavily guarded Japanese military arsenal in Baoding, surrounded by three layers of barbed wire.

To deliver the bomb into the enemy's heart, Yang Decai, the head of the Anti-Japanese Traitors Department, devised a plan: to let Ning Yachuan approach the daughter of the arsenal guard, Zhang Jinbao, named Qiaoyun, to gain internal intelligence. Although Qiaoyun came from a family of traitors, she was pure, upright, and discerning, and gradually developed a fondness for Ning Yachuan's impersonation. However, tragedy struck unexpectedly when Ning Yachuan was caught by Qiaoyun while testing the bomb in the jujube grove outside Lianggezhuang Village in Yixian. The girl recognized that it was not ordinary explosives, and in fear shouted, 'I will tell my father to arrest you,' putting the operation at risk of falling apart at any moment.

In an instant, Ning Yachuan faced an unsolvable dilemma: on one side was secrecy and the safety of his comrades, on the other side was an innocent teenage girl. The soldier's instinct ultimately overpowered his humanity; he grasped Qiaoyun's throat, and a few minutes later, the jujube grove returned to silence, with the scratches left on his body by the girl's arms becoming the final mark. The murder shocked the Jinchaji First District, where the Eighth Route Army strictly prohibited harming civilians, and Qiaoyun, as a target of united front work, was silenced, which was a serious offense. The villagers were furious, and the Anti-Japanese Traitors Department drafted a 'death sentence' report. Ning Yachuan offered no defense and voluntarily locked himself in a confinement room.

The report was escalated up to the commander of the First District, Yang Chengwu, who found himself in a dilemma: Ning Yachuan was a tactical genius who had previously single-handedly blown up bridges, annihilated hundreds of enemies, and captured the enemy radio team leader. His ability was crucial for bombarding the arsenal and stopping the poison gas sweep; killing him would uphold military law but might miss the opportunity to break the deadlock. The matter eventually caught the attention of Nie Rongzhen, who prudently instructed: considering the overall situation, whether to keep him depended on 'family understanding.'

An absurd yet realistic negotiation ensued: Yang Decai visited Zhang Jinbao with cakes and ten silver dollars, laying out his compensation intentions and proposing that if Zhang understood, the old debts on the 'must-kill list' for father and son would be canceled, saving their lives. Zhang Jinbao, heartbroken over the loss of his daughter and understanding the difficulty of survival in chaotic times, ultimately accepted the silver dollars, trading his daughter's life for the safety of his family. Ning Yachuan was allowed to return from the execution ground, carrying Nie's directive for 'deep reflection and atonement through achievements,' beginning his path of self-redemption.

In mid-September, Ning Yachuan took advantage of the gap in air defense provided by Zhang Jinbao, disguised as a laborer carrying a box of 'Majia Xiangpu' pastries to blend into Baoding City. On the night of the operation, he caused a small explosion and fire at the Grand Theater in the southern part of the city to divert the Japanese military police, and during the moment of vulnerability at the western suburb military arsenal, he calmly placed and detonated the bomb. A batch of ammunition capable of equipping a regiment turned to ashes, and the mission was successfully completed. However, Ning Yachuan had changed; the once cheerful 'lone wolf' had become silent and more desperate in combat, as if trying to make up for the guilt from the jujube grove.

In 1944, during the operation to rescue American pilots, Ning Yachuan charged ahead and sacrificed himself heroically while covering his comrades and the allies, never mentioning Qiaoyun again nor leaving a word for his family. He fulfilled the promise of atonement with his life, and the choice made in the jujube grove became an eternal regret, while this struggle and redemption amidst war also became a heavy footnote of humanity and mission in a special era.