“The Gathering Storm” is Volume 12 in Robert Jordan’s Wheel of Time series. Unfortunately, Mr. Jordan passed away before the series could be completed, so Tor hired Brandon Sanderson to finish the series. Originally slated to be one book, the end of the series has now been split into three volumes, the first of which is “The Gathering Storm.”
The audio chapters are available to those registered on Tor.com. See: http://www.tor.com/gatheringstorm/register
Further info on the book can be found here.