I think this is the conclusion of this particular trilogy, although I don't know for sure. It feels like a conclusion, anyway.
Apprentice wizard Conn is trying to find a way to protect the city of Wellmet--specifically, the city's magic, a living being--from a predatory magic. Conn is hampered since he still doesn't have his locus stone that allows him to work magic. He's also hampered by the city guards, who are convinced he's nothing more than a thief, and by the city's other wizards, who don't believe the magic is alive and don't believe it's under threat. With his mentor's help, Conn casts a spell to help him find his locus stone--a spell that leads him far away from Wellmet when the city needs him the most.
When I first read this book, I was a little disappointed. When Conn leaves the city, I didn't expect that part of the story to last so long. I kept itching for him to get back. But that was just me; now that I think about it, Conn's trip to find his Locus stone is a key part of the whole trilogy. That's where he discovers what the magic really is. I was just being impatient.
As always, I enjoy Conn's reticence and practicality along with his clever sense of wordplay. These are fun books to read and I daresay they'd be fun to read aloud. I hope there's more in this series, but even if there aren't, I like the ending a lot.