When you try to checkout a Kindle title, if you see an error page like this:
or like this:
this means Amazon either no longer offers this title in the Kindle format (and we haven't been notified about it until a customer discovers it, just like you have in this instance) or there's simply a problem with this title. Fill out the support form on this page so we can open a ticket with OverDrive.
In the meanwhile, you can still enjoy this title by reading it in your browser on your Kindle Fire, desktop, laptop, or phone. What's neat about reading the title in your browser is that it will automatically synchronize your reading progress across devices and you can even download a copy of the title to read if you lose your internet connection. This page has directions that will show you how to read a title in your browser.