I have the opportunity to save cassie from don.. but when i do it always ends in me having to leave and it completely ends. i want to save cassie and also keep playing.  i have Transylvanian, the  milk farm,  abandon town, and New Ark opened.  what am i missing?

Also, are there any other places then the ones i have unlocked-

You need a certain NPC's help to save Cassie without the game ending. After talking to one of the NPC's who tells you they can't do anything unless something happens, something in the slums will be different

That's all the locations for now!