Actually, I had a bit of a false start - I thought I was finished, somewhat prematurely. I was just reading through everything with John, in preparation to emailing the roughs off to Hodder (it can be very useful to have a 2nd pair of eyes - John often spots things I've missed). It was all looking good though. Lots of chaos and plenty of children flying through the air...
Anyway, we read the last spread and the story ended rather suddenly. It was only then that I realised I had missed off the end! There's always a final single page, the one you get after the final spread. It's not always used - it depends on the book and the length of the text. In this series of books, that final page is always a sort of cautionary ending, sometimes with the hint of a sting in the tail.
I worked out what went wrong: when my art director printed me a slightly reduced set of layouts to work from (blank pages with just the text), the single page had got forgotten at her end. I didn't notice because of not working through the illustrations in order.
So, I had to go back to the drawing board (literally) and get scribbling again. This is what I came up with (the little girl will of course be wearing a red dress):