How do the sequels affect this? I read this once more in the same discussion so I am curious. Let's assume the 1st book goes public. I should be able to use th

How do the sequels affect this? I read this once more in the same discussion so I am curious. Let's assume the 1st book goes public. I should be able to use those characters and their known relationship in any which way, no? What's wrong with that, copyright wise?