The Halfblood Chronicles is a trilogy of fantasy books written by Andre Norton and Mercedes Lackey. The series is set in a mystical world of elves, wizards and dragons. The series is released by Tor Books, and comprises Elvenbane (1991), Elvenblood (1995), Elvenborn (2002), and Elvenbred. Elvenbred, the fourth book in the series, has not yet been released. Due to the death of co-author Andre Norton it is stated that the series fourth book has been handed over to Mercedes Lackey, and has yet to be published as of December 2022. Source: Wikipedia (en)