Rogue Berserker

Harry Silver had already had a lifetime of trouble from Berserkers, the automated killing machines which were armed with weapons powerful enough to sterilize a planet and programmed eons ago by a now-extinct race to denude the galaxy of life. After losing his merchant spaceship in a recent battle with one of the death machines, he faced economic ruin.
Then Winston Cheng, one of the wealthiest humans in the galaxy, offered to buy him a new top-of-the-line ship in return for doing a job. While the two men talked, a holograph of a young woman and her child played over and over. The woman was Cheng's granddaughter. She and her son were Cheng's only surviving descendants - and they had been kidnapped from their space yacht by a Berserker. Cheng wanted to hire Silver to rescue them.
The offer would have been tempting if Silver hadn't thought the job was not only too dangerous, but likely to be futile, as well. Berserkers usually killed humans outright, in accord with their programming. When one of the killer machines took humans alive, it was invariably for experimentation, trying to determine what made their human enemies tick and looking for a weakness to exploit. Silver was certain that Cheng's loved one's were dead by now, or, if alive, no longer recognizable as anything human. And Silver had barely survived his previous encounters with Berserkers. So he declined Cheng's offer - until Silver's own wife and daughter were similarly kidnapped by a Berserker, possibly the same one.
Silver now had nothing to live for but revenge. Cheng's offer was still open, and Silver quickly joined the assault team, but not without suspicions which he kept secret. The timing of the abduction of his wife and daughter could not be a matter of chance. Someone on Cheng's team must have leaked Silver's name to the Berserkers somehow. He also thought it suspicious that an old acquaintance with a strong grudge against him was also on the team. Before the mission was over, Silver would find that his wildest suspicions fell far short of the truth. And he would find himself in an alliance he could never have predicted - one which he was unlikely to survive.