After Debra’s death, as you might expect, Google Alerts started going nuts. I had alerts up for her name and various of our book titles and the hits kept coming.
One such led me to Locus Online:
School of Wizardry (1990) launched the Circle of Magic series and had sequels Tournament and Tower (1990), City by the Sea (1990), The Prince’s Players (1990), The Prisoners of Bell Castle (1990), The High King’s Daughter (1990), Mystery at Wizardry School (2003), and Voice of the Ice (2003).
The surprising things were these two books: Mystery at Wizardry School (2003), and Voice of the Ice (2003). Doyle and I did not write them. They were produced and published without our knowledge, without our permission, without our participation, and, needless to say, without paying us.
The Circle of Magic series has six books, and six books only. It is called “Circle” because the end returns to its beginning, and the plots and characters are carefully braided throughout the series.
Again, Mystery at Wizardry School (2003), and Voice of the Ice (2003) are bogus. They are fake. They do not include my plotting or Doyle’s writing, our knowledge of the Middle Ages, our style, or our skill.
These two are pirate books.
To the best of my knowledge they were never released in the United States.
JAMES D. MACDONALD 
Hi read this series as a kid and I just came across this post and it seems so crazy that someone published a book under yours and Doyle’s names. Did you ever discover who had written the last two books and gotten them published?