I wrote a flash-forward prologue that is all action.
I moved some chapters around, not introducing the third thread until further into the book so there aren't so many characters coming at the reader all at once.
I've strengthened the motives of two of the main characters.
I put one character's chapter at the very end of part one.
I addressed all the smaller concerns -- mis-named characters, etc.
So...I think it's stronger. Maybe not kickass, but enough that if the agent/publishers are willing to give me the benefit of the doubt and trust the book will be stronger by the end, they would be willing to take it.
If they don't have goodwill toward me, I'm probably out of luck anyway. There are almost as many disadvantages as there are advantages to dealing with the mainstream, so I'm not going to freak out about it.
The book is everything.
5 days ago