Top edge

Shen Siwei awakens from a twenty-year cryogenic sleep in a high-tech military laboratory, his body rebuilt with ultra-high molecular materials that render his skin bulletproof and his muscles stronger than mechanical prosthetics. Colonel Moran, his former captain and now superior, reveals that Shen Siwei is the sole survivor of a mission where his entire team perished. Despite his enhanced physique, Shen Siwei’s cardiopulmonary function remains fragile, requiring a magnetic oxygen mask that adheres directly to his face. Moran assigns him an urgent investigation mission in Z City, located in the lower district of the Tree of Life, a massive vertical structure where society is stratified by altitude. The lower levels are plagued by "flowing people," criminals exiled to the harsh desert outside who have recently breached the outer defenses under the leadership of a mysterious figure named Klet.

The mission requires Shen Siwei to infiltrate Z City disguised as a noble negotiator from Marg, the ruling aristocracy residing at the top of the Tree. To facilitate this, Dr. Chen alters Shen Siwei’s appearance, changing his hair to gold and his eyes to blue, and implants false memories to help him maintain his cover. However, the memory implantation fails, leaving Shen Siwei unaware of his supposed romantic relationship with Moran, a fact Moran claims they shared. Unsettled by Moran’s physical affection and the hidden agenda behind his revival, Shen Siwei proceeds with the mission anyway, descending to the lower levels where sunlight is scarce and tension is high.

Upon arrival in Z City, Shen Siwei’s convoy is ambushed by assassins who manage to kill his two military escorts. Shen Siwei survives the attack unscathed, displaying combat skills that betray his civilian cover, and proceeds to the city center to find Klet. He is captured by Barn, Klet’s brutal second-in-command, and imprisoned in an iron cage in a public square as part of a humiliation ritual. Klet arrives, dismisses Barn’s insubordination with a single coin, and rescues Shen Siwei, taking him to a self-service hotel under the guise of sending him away. During the ride, Klet suspects Shen Siwei’s true identity due to his familiarity with gunfire and his physical resilience, leading to a tense confrontation where Klet searches Shen Siwei for weapons.

At the hotel, Klet installs a listening device outside Shen Siwei’s room and monitors his movements. Shen Siwei discovers the bug but maintains his cover, eventually escaping through the window to survey the heavily guarded energy station, the true objective of his mission. He returns to the hotel, where Klet confronts him, having deduced that he left the room. The two engage in a psychological duel, with Klet testing Shen Siwei’s reactions and Shen Siwei carefully masking his military background. Later, while driving Shen Siwei to a grand hotel to evade surveillance, Klet is stopped by police drones for traffic violations. When the drones open fire, Klet hands Shen Siwei a gun, forcing him to choose between maintaining his civilian disguise or defending himself, escalating the danger and deepening the mystery surrounding Klet’s true motives and origins.