 The events of that book wrapped up most of the series' loose plot lines, although it did not bring the series to a definite ending.In the same talk, Peters stated that installments written after that point would "fill in the gaps" in the series' chronology, as there were gaps of several years between some volumes.The next (and last) book to be published, "A River in the Sky" (the 19th book in publication order) was retroactively inserted into the series chronology as the 12th book.