Do Amari and Polly become fast friends on their journey that begins in Part Seven? Why or why not?

No, Amari and Polly must navigate many difficult emotions. They do not immediately trust one another simply because they are on this journey together; in fact, they still harbor their old resentments and prejudices. They stay together because they know that they are stronger in number, not because they agree about their options or feel they can trust each other.