Vendetta — Peter David

The Borg--half organic being and half machine, they are the most feared race in the known galaxy. In their relentless quest for technological perfection, they have destroyed entire star systems, enslaved countless peoples, and, in a single brutal attack, decimated Starfleet's mightiest vesels. Only a final desperate gambit by Captain Picard and the U.S.S. Enterprise crew stopped the Borg from conquering the entire Federation. And now they have returned.

Answering a distress call from a planet under attack by the Borg, the U.S.S. Enterprise crew meets Delcara, the lone survivor of an alien race the Borg obliterated. Blinded by hatred, Delcara seeks the ultimate revenge--the complete destruction of her race's executioners. But the U.S.S. Enterprise crew learns that Delcara's vengeance carries a terrible price, for once unleashed, the destructive force she commands will annihilate not only the Borg, but countless innocents as well...