Back Room Adventure Starts with a Delivery Box

A strange express box suddenly appeared, pulling me into a dangerous journey into the back room. For a billion dollars, I decided to fight! But there seems to be something more dangerous here... Hunted by entities, betrayed by my companions... With no system or powers, I fell into a dangerous and desperate situation... For the sake of development! Level 503, survival difficulty 5. I started a head-on confrontation with the "Lord of the Back Room"... The front hall has long been in chaos due to missing persons, and the conspiracy in the back room has gradually surfaced... Death, riots, desperate situations... The lives of humans in the back room hang by a thread. Where did I come from? "Be obedient and let me slaughter you!"