I enjoyed the Xindi arc but wondered if the writers ever chimed in on its evolution. I know why the arc was created-to generate interest in the series--but I wonder when certain ideas and elements came to them--Did they know the purpose of the spheres all along, were the Sphere Builders always meant to be the Xindi's Future Guy, was the book in Exile going to have more of a role in the arc but was dropped, was FG/Suliban ever considered to be brought into the arc etc.