??? Look way down the file browser list (Misc). Are there extra files (other than the few normal ones)?
Your book may have been built incorrectly and they could not be placed properly.
If this book arrived in this condition, Get Amazon to send a corrected version. If it got damaged later, good luck, because it is fixable, but a simple 'do this' is not possible.
Use the U(npack ) tool in Calibre, and see if you can grab out tha broken pieces, then use the editor to put them back (or make a separate book)