It's a full - length preview of the fourth and final book in the Tales From A Warming Planet series. (joefollansbee.com)
I'll try to make this spoiler free, since there are some details that can be assumed since this is the third and final book of the series. (goodreads.com)
The rest of the process includes you receiving a proof to OK before final books are printed. (selfpublishing411.com)