Contractor of All Realms

Young Gu Chen awakens to the stepless black coffin "Xuanmo", which can preserve contracts, memories and civilization abandoned by the world, but at the cost of forgetting a piece of the most precious past every time he opens the coffin. In order to find his missing mother, he and Su Zhaoxue, a contractor from White Deer City, stepped onto the fourth railway track, only to discover that an old world that should have been destroyed was sealed behind the black coffin door. Open the door, he may find his mother; close the door, he will give up all the forgotten people with his own hands.