The Halfblood Chronicles is a series of four 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 4th book has been handed over to Mercedes Lackey, and has yet to be published as of May 2021. Source: Wikipedia (en)