InkSpout , I agree wtih Christopher Roy Denton .

I do not see this as an automatic exclusion for publication. First, write your piece.

Remember 50 Shades of Gray? It began as fanfiction for Twilight... Which means it had the same main characters, Bella and Edward. The premise was they were a couple years older and would be involved in a a specific intimate relationship. This was not branded as plagiarism, but the characters were renamed before publication. I'm not sure what else changed. But both of those made quite a bit of money, and even into movies.

You could compare Harry Potter to Narnia in the way that they are both British boarding school novels. They're not the same, but they have a few basic ideas in common. And your execution of that idea will be different.

My current project, that I'd like to publish, has enough of a semblance of Firefly that about half (or a few more) of the readers have recognized and pointed that out. I don't mind. It'll still be publishable when I finish it.