Ending on a lefthand page in a book where chapters start with a spread

I have set up a book where all chapters start with a spread (1st page a lefthand page). When I get to the end of my 15 chpt. book, I need the last page to be on the left. ID CS6 obediently will not allow me to add just one page 'cause it's expecting another chapter which will start on the left, so it demands ending the chpt. on the right. How  can I overcome this?

Thanks