Wen Yan, a recent graduate from the twenty-first century, unexpectedly transmigrates to another world overrun by demons and ghosts, where human life is worth less than grass. The moment he arrives, a wandering evil spirit attacks him. At death's door, he activates the golden finger he received through transmigration: the Underworld Summoning System. The System can impose rules on chaotic supernatural forces, allowing Wen Yan to summon departed souls from the Underworld to fight, exchange for items that seal demons and ghosts, and earn soul power by completing missions so he can level up. It gives Wen Yan a slim chance of survival in his desperate situation.
At first, Wen Yan is an ordinary person with no supernatural abilities. His frail body cannot be trained in the local cultivation arts, so he has to rely entirely on the souls summoned by the System. But summoning powerful souls costs a great deal of soul power, and if he overuses it, the spirits will turn on him and kill him. To survive, and to protect the displaced people like him, Wen Yan sets himself a goal: to build a city and a power of their own for humanity, so people will no longer be slaughtered by demons and ghosts.
The three demon and ghost lords who rule this region refuse to let humanity rise. They repeatedly send their underlings to attack Wen Yan's settlement and sabotage the construction of his city. They even conspire with the leaders of other human factions to suppress him and seize his few remaining resources. Before the all-region ghost tide arrives, once every three months, Wen Yan must finish building the city, gather refugees, and increase his own strength. Otherwise, everyone under his protection will be devoured by the tide, and humanity will have no hope of rising again.
Through one life-and-death confrontation after another, Wen Yan uses the System's rule-based advantage to subdue powerful Underworld spirits, foil the demons' schemes, and gradually unite scattered human settlements. From a transmigrant with nothing, he grows step by step into a human leader capable of standing against demons and ghosts. Along the way, he continues
