System 1509 is also a special system among the many quick travel systems.
It is not a string of data residing in the host's body. It will be dropped into the mission world along with the tasker and become a living being in the world, helping the tasker in all aspects. The tasker can only determine who 1509 is by himself, and there is only one identification opportunity. If it is wrong and the mission fails, if it is correct, 1509 will perform the duties of a normal system.
System 1509 is used for the assessment of task workers. But one day, 1509 was infected by a virus and was mistakenly judged as a mission worker by the mastermind, and was thrown into mission worlds one after another.