A "short" (that was the plan, ok?) story continuing the tales of Tarrin Kael and his friends in Sennadar. Available in its entirety for free from http://forums.sennadar.com/ in the "Short Stories" section.
There is an author, who goes by the name of Fel. He releases his stories, chapter by chapter to the internet. They vary in genres, including fantasy and sci-fi. Several of these books are comparable in length to the epic story Les Miserable's, or longer.
Tarrin's work for the God of Gods has put him into an interesting situation. He's tasked to stop a war, and without using his preferred method of wanton destruction to both sides. Since subtlety isn't his strong suit, he ropes Miranda and a few others into the scheme to make a boy a king worthy of his crown, stop a war, and preserve the Balance of the multiverse.
As a "short" story (still the length of a long novel), this is an interesting addition to the canon. I actually hadn't been aware of this until my recent reread through the main series, so I was very happy to find a bonus story to cap everything off.
This is set several years after Demon's Bane, so it does help to have read the Firestaff series and the Pyrosian Chronicles first. Amazingly, it manages to introduce even more different types of magic (psyonics/will, which was very briefly mentioned in previous books but gets a fuller treatment here, plus some of the tricks Tarrin has picked up that he insists aren't magic but certainly behave that way).
I like that we do get several returning characters, although I wish Haley got a bigger role. But the returning characters also hamper the story a bit, as the characters from the new world tend to take a back seat to the ones imported to help Tarrin with his job.
I also found it fun how much of Polin's education centers around teaching him that even though he's the king, he doesn't have the power to fix everything, and he shouldn't try. That no matter what he does, people will still suffer, but his job is to do what he can where he can so he can be a good king.
Overall, this is more of an optional extra for those who liked the main series. It serves to answer a few lingering questions (Telven, Haley, and what's up with Tarrin's alter-ego on Pyrosia), and provides a bit of fun in a new place, but doesn't impact the characters or the world too heavily. I rate this book Recommended.