In the early days of the Republic of China, a mysterious murder at sea draws Zhang Haiyan and his partner into an investigation that quickly spirals into a dangerous conspiracy. What begins as a search for truth aboard the massive ship Nan'an becomes a fight for survival in a world of intrigue and betrayal.
The mystery began in Balai, Nanyang, during what was supposed to be a joyous wedding ceremony. Amidst the celebrations, a putrid, sickening stench suddenly filled the air, originating from a bizarre wedding gift presented by the clan. The bride and groom were urged to abandon their mortal bodies in exchange for everything a human could ever desire. Not long after, the mutilated corpses of the groom's family were discovered in a salt marsh deep in Nanyang.
Zhang Hailou and Zhang Haixia smuggled themselves into Xucheng by playing dead to avoid paying the steep head tax. Upon entering, they found the city in ruins, littered with lifeless bodies despite no reports of plagues or bandit attacks. Upon closer inspection of the corpses, Zhang Haixia noted a bluish-purple coloration on one victim's face and an angle of compression on the neck, indicating death by suffocation. Another body nearby had slit wrists.
Following their decision to venture into the depths of the reef cave to resolve the crisis, Zhang Hailou and Zhang Haixia made their way inside despite the desperate warnings of onlookers to stay away. Inside, they discovered a calcified Ming Dynasty shipwreck that had merged completely with the surrounding reef, filling the damp air with a heavy stench of rotting flesh. Deep within the ship's hold, they found decayed corpses suspended in bags.
Deep in the rainforest, an archaeological expedition team led by Professor Warner had been excavating for months in search of ancient treasures. Suddenly, a mysterious, disguised woman carrying severed arms breached their camp. Recognizing a dark black magic curse, she sought out Warner to make a deal. The woman was actually Zhang Haiqi in disguise.
Determined to uncover the truth and save Zhang Haixia as quickly as possible, Zhang Hailou began his investigation on the Nan'an. To gather clues, he played cards with three crew members, deliberately losing money to get them to talk. Once Steven grew tired of watching him lose and stepped outside after lending him some money, Zhang Hailou distributed the cash among the crew.
In a deep shaft in the ship's hold, Zhang Hailou discovered a body trapped by a living Evil God. Seeing flies swarming around it, he deduced the person had died recently and decided to climb down to investigate. He instructed Steven to stay above as a lookout. If any danger arose or if the creature reanimated, Steven was supposed to break the head off a small hostage statue they had; otherwise, they would both be doomed.
Zhang Haixia was not trapped in a fantasy. He knew he had been poisoned because he smelled the distinct stench of cured meat when he first met Chen Xifeng—a foul odor that went entirely unnoticed by the others on the ship. Realizing his perception was altered, he knew his mind was playing tricks on him. Despite his paralyzed legs, his intellect remained fully functional, allowing him to set a series of traps in his room to capture his assailant.
He Jianxi slowly regained consciousness after being in a coma for an entire day, only to find himself confronted by a startling truth. He asked the man before him if he was truly the infamous Plague. Zhang Hailou merely smiled, praising Jianxi’s incredibly sharp sense of smell, which allowed him to detect even the faintest trace of turmeric. The talent strongly reminded Hailou of his close friend, Zhang Haixia. Hailou had already packed up almost all of Jianxi’s belongings.
Fleeing the pursuing assassins, Zhang Hailou used his exceptional martial arts skills to carry He Jianxi up to the third floor, slipping into Steven's private bathroom while the killers searched the lower decks. Exhausted and weak, Zhang Hailou revealed to He Jianxi that he had been poisoned. He Jianxi sarcastically remarked that as the dreaded Plague, Zhang Hailou should have planned for such a setback. Ignoring the banter, Zhang Hailou focused on their immediate survival.
During the chaotic struggle in the cargo hold, Zhang Hailou fought desperately against the onslaught of assassins. He Jianxi remained in the shadows, using his keen senses to monitor the surroundings and warn Zhang Hailou of incoming threats, shouting that the attackers were trying to wear him down. However, the killers eventually noticed He Jianxi and charged at him. Zhang Haiqi suddenly intervened from the darkness, effortlessly dispatching the threat and saving He Jianxi's life.
Zhang Hailou and He Jianxi finally arrived in Xiacheng, exhausted from their long journey. As they stepped ashore, Zhang Hailou looked around, his mind drifting back to a memory of Zhang Haixia. He recalled how he had promised to take him to Balongzhou to make a name for themselves, so they could eventually return to Xiacheng in glory to see their mentor.
In the Dong Residence, Zhang Hailou is devastated by the revelation of his past mistakes. He demands to know who the woman posing as Miss Dong really is and where his master, Zhang Haiqi, is. She coldly lies to him, claiming his master is dead along with everyone else except the two of them.
Zhang Haiqi returned to the Dong Mansion, heavily wounded from her previous encounter at the military base. Recognizing the imminent danger, she urged Mr. Dong to take his family and flee Xiacheng immediately, suggesting they go out to sea. However, Mr. Dong refused to leave her behind. He reasoned that because they were in the foreign concession and she was widely known as the daughter of the influential Ship King, no one would dare to make a move against them.
Zhang Hailou finally steps into the Southern Archives, a moment he has anticipated for ten years. His companion, who is posing as He Jianxi, marvels at the spectacular sight and asks what the Archives actually does. Zhang Hailou explains that it was a secret organization under the Maritime Supervisory Office, dedicated to investigating and cataloging all the bizarre anomalies of the southern lands.
Lu Junxiang cornered Zhang Haiqi, confidently declaring that she had run out of places to escape. However, Zhang Haiqi remained unfazed, having already prepared a way out. Just as Lu Junxiang's men rushed into the chamber, the ocean water that had begun pouring into the underground ruins suddenly breached the walls, violently flooding the area and sweeping the henchmen away. Seizing the opportunity, Zhang Haiqi pinned Lu Junxiang down by trapping his leg under a massive boulder.
Continuing from their long separation, the two brothers finally reunite. Overjoyed to see his brother awake, Zhang Hailou eagerly moves in for a warm embrace. However, their mentor, Zhang Haiqi, interrupts the emotional moment by tossing an object that strikes and lightly injures Zhang Hailou. Though Zhang Haixia is happy to be awake, he secretly senses a strange, inexplicable sensation stirring deep within himself.
Zhang Haixia and Zhang Hailou spent the evening drinking together at home. After Hailou drank too much and lamented that things might have been different if he had been the one crippled, he fell asleep at the table. Seeking some fresh air, Haixia went out into the streets. There, he came across a group of drunk thugs viciously tormenting a helpless beggar.
Zhang Haixia did not want his mentor, Zhang Haiqi, to carry the heavy burden of guilt, so he expressed his desire to handle their enemy, Mo Yungao, himself. Although Zhang Haiqi was deeply concerned about his physical state and the consequences, she ultimately respected his decision. Having spent three agonizing years paralyzed in Nanyang under the selfless care of Zhang Hailou, Haixia desperately wanted to prove he was no longer a burden to anyone.
During the confrontation with Zhang Changlin's men, the situation takes a bizarre turn. As Changlin attacks Zhang Haixia, a strange, crazed persona seems to take hold of Haixia. Muttering violently, he pulls out a grenade, prepared to blow up his attacker and himself. Zhang Hailou watches in utter disbelief, barely recognizing his brother. Fortunately, Changlin manages to dive away just before the explosion.
Adjutant Zhang Changlin escorted Zhang Haiqi and Zhang Hailou into Zhang Qishan’s residence. Zhang Qishan invited them to sit, dryly noting that while he rarely welcomed members of the Zhang family, he could not simply throw them out since they had already arrived. Zhang Haiqi skipped the pleasantries and prompted Zhang Hailou to state their business.
Zhang Haiqi and Zhang Hailou carry out their daring plan to infiltrate Mo Yungao's special train as it speeds through a dark mountain tunnel. Waiting in the shadows, they have a mere twenty seconds to make their move. They successfully leap onto the moving carriage, swiftly neutralizing two unsuspecting guards who were casually discussing their post-trip drinking plans.
Following the destruction of the secret base, Zhang Haixia made a phone call to Mo Yungao, coldly informing him that his men had been completely wiped out. Identifying himself as an agent of the Southern Archives, Haixia noted that Mo Yungao once possessed a conscience and questioned why he had fallen so low, asking where people like them would ultimately end up.
Zhang Hailou woke up aboard a train heading deep into the vast mountains of Nanqiang. Sitting across from him, his mentor Zhang Haiqi handed him the research files on Bailejing, a legendary paradise hidden within the wilderness. Zhang Hailou noted the reports of rampant bandits, poisonous pests, and a fierce populace, which made entry almost impossible for ordinary people. When asked, Zhang Haiqi recalled investigating an unsolved case there years ago.
Following Mo Yungao's instructions, Zhang Haixia led an advance party of four warlord soldiers to scout a roadside inn, which served as the primary gateway to Bailejing. Unbeknownst to them, the inn was run by the local bandits of Phoenix Fortress. Spotting the heavily armed soldiers arriving late at night, the proprietor and his son, Xiao'er, quickly hid their guests and prepared for a potential confrontation.
After kneeling and calling Zhang Haiqi his "mentor's wife," Zhang Qianjunwanma points to a portrait of a woman from behind, explaining that she was the woman his mentor, Zhang Qianzhang, loved most in his life. Decades ago, Zhang Haiqi had been severely injured in the mountains and fired a flare to summon help from the Zhang family. It was Zhang Qianzhang who answered the call, falling in love with her at first sight.
As Zhang Haixia traveled by raft toward Bailejing, he was accompanied by three soldiers assigned by Mo Yungao. One of the soldiers tried to ease the tension, hoping Zhang Haixia would not hold their past conflicts against them. Deeming the man far too noisy, Zhang Haixia swiftly executed all three soldiers, leaving their bodies behind as he continued his journey alone. Inside Bailejing, High Priest Su Ya was receiving a local family whose young boy he had recently saved.
Zhang Hailou is furious when Zhang Haiqi abruptly calls him back, as he had been on the verge of waiting for Zhang Haixia. When Hailou confronts her about hiding the truth, she warns him against seeking his adoptive brother out. Hailou points out that Haixia slaughtered everyone in Priest Su Ya's mansion and hung the priest's corpse on a water cart just to avenge them, proving he has lost his mind.
In the quiet of the woods, Zhang Haixia crossed paths with two local men who were searching for the tattooed outsider (Zhang Hailou). Unaware of Zhang Haixia's true identity, the men vulgarized the outsider who had allegedly run off with the Mountain God's bride, suggesting they would castrate him once caught. One man even boasted about taking the beautiful bride as his own concubine.
Following his mentor's disappearance into the secret passage, Zhang Hailou was forced to disguise himself as the bride to keep up appearances. He was soon brought to the altar at the Feikun Balu Temple, where the locals gathered for the wedding ceremony. The auspicious hour arrived, and the crowd called for the great Feikun Balu to accept his bride. However, the ruse did not last long. The locals quickly realized the bride was actually a man.
Zhang Hailou’s rage boils over as he faces the unrecognizable version of his brother, Zhang Haixia. The two clash with equal fury and skill, trading blows in a tense stalemate where neither can bring themselves to deliver a lethal strike. Their duel is cut short when the sky begins to rain the ominous pollen of the Twilight Grass. Realizing Mo Yungao’s devastating plan has succeeded, Zhang Haixia points out that their commander has finally achieved his goal.
Zhang Haixia, operating under his masked persona, Heixia, confronted Mo Yungao. Holding him at gunpoint, Zhang Haixia cold-bloodedly questioned if even immortals could withstand bullets. Mo Yungao, realizing his defeat, admitted he had not misjudged the young man's formidable nature. Addressing him as Adjutant Mo, Zhang Haixia declared that he would personally fulfill his dying wish. In his final moments, Mo Yungao recalled an old prophecy concerning three adjutants meeting their ends to realize a grand plan.
Zhang Hailou dragged Zhang Qianjun through the subterranean passages. Recovering from his near-death experience, Zhang Qianjun suddenly remembered a vital piece of information. Years ago, his mentor, Zhang Qianzhang, had sent a confidential file to the Archives. The document detailed how the ancestors of the Zhang family had once explored Nanqiang and encountered an ancient, mysterious tribe called the Wupi Tribe deep in the mountain forests.
In the aftermath of his injuries, Zhang Hailou regained consciousness and shared a startling realization with Feng Huang. He explained that Zhang Haixia’s body was host to two completely separate minds. While they shared physical senses like sight, hearing, and touch, they remained entirely blind to each other's memories and thoughts. Trapped within his own mind like a prisoner, the true Haixia was powerless while the malicious entity Hailou named Heixia (the dark consciousness) controlled his actions.
