So, I found out a few months ago that I'd missed the release of Bastion, book 5 in Mercedes Lackey's Collegium Chronicles. A trip to the library remedied that issue, and I'm happy to report that it's a welcome addition to the Valdemar canon.
I'm still unsure if the rumor about this series being her last foray into Valdemar is true or not, or even if this is the last book in the Chronicles. I can see where it could be, since she tied up one of the bigger loose ends left from Redoubt, however, I find myself not wanting it to end here. Then again, characters in Valdemar seem to either die at the end of their story, show up as cameos in other stories, or in Vanyel's case, both. As much as I disliked the Chronicles at the beginning, Mags and Bear and Lena and Amily have grown on me. Particularly after Mags' dialect stopped interfering with the flow of the dialogue.
So, Bastion starts with Mags returning to Haven from his rather arduous trip to Karse courtesy of his old people. Since it becomes increasingly obvious the people his parents came from aren't going to stop trying to kidnap him back to whatever land they come from, a way is found to send all of our protagonists on Circuit concurrently, with the idea of faking Mags' death somewhere along the way to get the Sleepgivers off his back in perpetuity.
Thus Mags goes riding off with Herald Jakyr for his circuit, hitching up later with Lena and her mentor Lita (Head Bard at the Collegium who also has a history with Jakyr) and Bear and Amily, who are spreading around the herbal healing packets Bear started a few books back to help in cases where a Gifted Healer is unavailable (or the herbs can save a Gifted Healer's energy, etc.)
The sextet sets up a hub in The Bastion, a series of caves in the middle of the area of the circuit they're riding. As it turns out, the caves were once part of a Vale used by the Taledras (Hawkbrothers), and the caves were home to the hertasi (lizard folk). The caves were also where the bandits found and killed Mags' parents back before Book 1.
After visiting a few villages and towns as part of the circuit and facing various difficulties with them (one is indifferent, one is in revolt, and one is essentially a model town), the group gets snowed in by a blizzard. Which gives Mags time to go exploring other caves in the system, looking for clues as to the identity of his parents. Where he meets a character I refer to as Deus ex Machina, who more or less solves the riddle of Mags' existence over the course of a chapter. (Seriously. He becomes a much more interesting character after the Great Reveal, but his presence and back story are a bit... shoehorned. Plus he's essentially an Amish Assamite.)
As the book ends, it looks as if all the major plot elements of the series thus far have been resolved one way or another, although I really hope there's another book discussing what happens after. Because, really, there are other stories that I'd love to hear told from this particular period.
Which really is a sign of how much it improved as it went on.