During the summer break of his freshman year, Lu Ding plans to take an internship and earn some extra spending money. But who could have expected that the construction site where he works would unearth a bleeding stone? While all the workers flee in terror, Lu Ding is the only one who grabs a demolition drill and charges forward. Having transmigrated into this world nearly twenty years ago, Lu Ding's cheat ability, a Monster Containment Prison, has been ready and waiting. Unfortunately, he hasn't encountered a single monster in all those years, and his patience has long since run out. Now that a monster has finally appeared, he has only one thought: either kill the monster or get killed by it. He joins Bureau 749, using its resources and connections to track down and contain monsters.