Book 4, final. The system is no more, as are many of the abilities that it gave, but along with this the restrictions went away. Polina chose her path, accepting her new tribe and the path of the demonic beast, but this did not lose her desire to help at least something to their former homeland. But in order to help, you first need to find a way back, and how can you look for it when the tribe has much more important tasks?