Elvenbred. The Halfblood Chronicles, #4

After a twenty-year wait, the legendary Halfblood Chronicles reaches its finale in Book Four - written by Mercedes Lackey and Ben Ohlander, in memory of Andre Norton. The elves did not conquer because they were strong. They fled because something stronger was hunting them. On the elves' original homeworld, the last great cities stand behind failing shields while monstrous Predators batter at the walls.
Lord Haldeen Gatekeeper knows the truth his rulers refuse to face: the creatures are not mindless beasts. They are learning, adapting, and closing in. Desperate to save his city and the rank he has clawed up from nothing, Haldeen reopens the forbidden World Gate that once carried the elven exiles to a new world. His secret experiment sends a living probe through the ancient portal - and drags back something he cannot begin to understand: Lady Triana, not long ago one of the most dangerous players in the courts of the world her people once conquered.
Triana has survived intrigue, rivalry, and every poisonous game of elven power. She has never survived being powerless. Here, on her own kind's first world, she is no one - collared, stripped of her magic and status, catalogued as a specimen and worked as a slave. The collar her people perfected to break others now closes around her own throat. Her one ally is the creature she names Rock: another captive, chained by the same brutal magic, as trapped as she is.
If Haldeen succeeds, the Gate will open wide, and a starving elven civilization will pour through into the world the exiles once seized - a world now shaken by rebellion, by dragons, and by the very magic they tried to exterminate. If Triana fails, she will remain what her captors believe her to be: a useful sample, a convenient slave, one more body crushed as their world falls to the Predators. An epic of portal magic, monstrous warfare, forbidden experiments, survival, and impossible alliances, in the tradition of Anne McCaffrey's Pern.
Elvenbred completes the saga begun in Elvenbane, Elvenblood, and Elvenborn - at last.