If you own the Kindle version it is only $3.47 to purchase the audiobook from Audible! If you don’t own the Kindle version, the least expensive option is an Audible trial, or to request your local library purchase it. However, if you are an iBooks fan–or Audible is unavailable in your country–you can get it on iBooks, and it’s also available from Barnes & Noble.
It isn’t announced anywhere … but my publishers snuck The Fire Bringers in at the end, just like the slipped The Slip in at the end of Fates.