Danil knew that the universe is a system. But he couldn’t have imagined that the system’s protection would regard him as a harmful program and send him into a sandbox world, where it would test him—determining whether there was a harmful kernel inside him.
Besides Danil, hundreds of beings from all over the universe are copied into this world for testing, and very often they are infected.
Although many end up there simply because they are capable of something more than others. But even a harmful kernel can be hidden very deep—and it may not be detected just like that. So the system doesn’t release many back, and it’s very important to try hard to return.