The canonical works of the Interim Errantry group were begun to bridge some of the empty spaces in the narrative of the Young Wizards series. Their purpose is to fill in character backstories of interest to YW readers, and explore various kinds of wizardly business that don’t fit into the main continuity of Young Wizards novels.
As of this writing (late July 2017) there are six Interim Errantry works in two collections.
The first one, Interim Errantry (also now referred to as Interim Errantry 1), contains the 2011 novella Not On My Patch, the 2013 novelette How Lovely Are Thy Branches, and 2015’s full-length original Young Wizards novel Lifeboats.
The second collection, Interim Errantry 2: On Ordeal, contains three novelettes dealing with the Ordeal-driven backstories of three well-known wizards in the Young Wizards universe: Roshaun ke Nelaid (2016), Mamvish fsh Wimsih (2016), and Ronan Nolan Jnr (2017).
All six works are available at Ebooks Direct both in collections and as standalone ebooks.
The next volume in the series will be Interim Errantry 3: A Day at the Crossings. Please check this site for news on the new work in early 2020!