He has also edited three volumes in the series, The History of Christmas, Time Signature and How the Doctor Changed My Life.
The second of these takes as its starting-point Guerrier's short story An Overture Too Early in The Muses.
After contributing two stories to the anthology Life During Wartime in Big Finish's Bernice Summerfield range of books and audio dramas, Guerrier was invited to edit the subsequent year's short story collection, A Life Worth Living, and the novella collection Parallel Lives.
After contributing two audio dramas to the series, Guerrier became the producer of the Bernice Summerfield range of plays and books, a post he held between January 2006 and June 2007.
Guerrier's work is characterised by character-driven humour and by an interest in unifying the continuity of the various Big Finish ranges through multiple references and reappearances of characters.