I purchased Wool 6 from Kobo. Thank you Mr Howey for making it available at Kobo.
It looks like the table of contents is missing? All that was in it was the Prologue and Epilogue.
For those using Calibre... I ran it through Calibre and used the following when converting:
Under "Structure Detection -> Detect chapters at:":
//*[(name()='h1')]
and under Table of Contents checked "Force use of..."
Calibre seemed to do a good job of finding the chapters.
And Thank you Mr. Howey for making it DRM free.