Lin Zai finally manages to save the mysterious man, only for him to remain constantly on guard and even warn Lin Zai that zombies aren’t the only danger in the apocalypse.

Lin Zai finds himself in danger once again, only to be rescued by the mysterious man, who finally reveals his name.

The mysterious A-Leh is carrying out a mission he cannot reveal. Believing him to be a trustworthy companion, Lin Zai hopes he will stay at the camp.

After waking up, Lin Zai is shocked to discover that A-Leh has abducted him. It turns out that Lin Zai is the “immune individual” A-Leh has been searching for, possessing genes that make him immune to the zombie virus.

As an immune individual, Lin Zai worries that he might become a test subject. Although A-Leh acts indifferent, he secretly begins investigating what could happen to him.

Although A-Leh insists that his only responsibility is to bring the immune individual back, the way he protects Lin Zai is clearly becoming more than just part of the mission.

Lin Zai suffers another allergic reaction and collapses, prompting A-Leh to risk entering a zombie-infested town in search of medicine. Left alone, Lin Zai unexpectedly finds himself caught in a deadly plot against him.

After narrowly escaping death, Lin Zai tells A-Leh that all he wants is to return to the camp that feels like home, but A-Leh refuses to let him go.

Lin Zai and A-Leh encounter a mysterious man named He Yao, only to discover that he is a genetics expert once highly sought after by two major pharmaceutical corporations.

With armed forces hunting them down, He Yao admits that he once took part in research on the zombie virus and barely managed to escape from the research facility.

A-Leh collapses after being poisoned, giving Lin Zai the perfect chance to escape. But when he hears A-Leh calling out to him, Lin Zai decides to stay and save him.

A-Leh’s wound worsens, but his time with Lin Zai feels almost like an ordinary date from before the apocalypse.

A mysterious survivor suddenly appears and leads A-Leh and Lin Zai to a new camp, where they unexpectedly reunite with an old acquaintance.

Lin Zai faces a new choice: stay at the safe camp, or continue the journey with A-Leh?

Lin Zai clashes with A-Leh again, and in He Yao’s laboratory, he discovers a familiar zombie.

To save his zombified brother, Lin Zai decides to undergo immune-subject experiments in secret, keeping it from A-Leh.

The experiments begin taking a toll on Lin Zai’s body. Faced with A-Leh’s heartfelt confession, can he finally make a decision?

To save his brother, Lin Zai insists on drawing even more of his blood despite the risks.

Lin Zai is left in critical condition after losing too much blood. A-Leh personally gives him a blood transfusion and stays by his bedside all night.

Unwilling to give up on saving his brother, Lin Zai decides to undergo bone marrow collection, while A-Leh chooses to stay by his side and face it with him.

Lin Zai loses another important family member and gradually falls deeper into He Yao’s scheme.

After his brother’s death, Lin Zai loses his reason to keep living, while A-Leh officially turns against his organization for him.

With all of He Yao’s lies exposed, A-Leh and Lin Zai decide to face the organization’s forces together.