After the virus outbreak, the global order collapsed and logistics were cut off. The protagonist accidentally binds to the "Doomsday Express System". The system will randomly generate orders, requiring him to deliver specific supplies (which may be medicines, food, or even a living person) to designated customers at designated locations. Orders vary in difficulty, distance and risk. Complete orders to gain points, survival supplies, physical enhancements, and special skills (such as "short-distance space flash", "danger perception", "language proficiency - zombie language?"). There will be penalties for bad reviews or failures (such as attracting zombies, temporarily depriving skills). Future technological equipment can be redeemed in the system mall.
The protagonist struggles to survive, completes simple intra-city orders, becomes familiar with the system rules, and accumulates initial capital and credibility. Encounter the first wave of "customers" with ulterior motives or survivors who snatch supplies.
The scope of orders slowly expanded to include city clusters and even across regions, and the difficulty soared (needing to travel through heavily infected areas and mutant beast lairs). Create a temporary companion/escort team. Discover clues to the origins of the epidemic or human resistance hidden behind certain orders.
