(I know chapter 4 & 5 should have been next, but looking at the files I have, I had started coloring and re-lettering them. They have some pages that are still the originals, some that are updated, some that don't have the lettering, or either new or old coloring.)
Chapter 6 is the start of the color pages originally, but not at the very beginning. The first three pages were still black and white, I've since come back and colored one of those three pages. Two of the pages don't have any shading I notice.
You can see in a few places here, during this time and before I went through a phase of not drawing behind the word bubbles. Now it just seems odd.
I think this is technically the first time Annie fights a super-villain.
If you look closely when Annie's flying, both Grace and Zoe are getting out of the train, in advance of them appearing in the comic.