The Silent Bells is the yet-unpublished fourth book in the Ashtown Burials series.
Publisher Difficulties
Although the book is mostly finished (N.D. Wilson has said so and has released the first chapter to select audiences), it has still not been published. This is because N. D. Wilson's publishers for the first three books retired and the new publishers do not like the book in its present form. N. D. Wilson, however, is committed to publishing the book, saying that he would do so "even if I have to publish line by line on Twitter." We await further updates.