Cordelia and Aral Vorkosigan are expecting their first child. Before crafty old Emperor Ezar Vorbarra dies, he maneuvers a very reluctant Aral into agreeing to serve as regent for Ezar's young grandson Gregor. A plot to assassinate the Vorkosigans with poison gas fails, but the antidote, while effective, is also a powerful teratogen that poses a grave threat to the bone development of their unborn son. In a desperate attempt to save the fetus, Cordelia has it transferred to a uterine replicator—an artificial womb—to undergo experimental treatment that may partially combat the otherwise-fatal bone damage. Barrayar, due to its harsh environment, has fostered a deep loathing for mutations, and babies with even minor birth defects are routinely euthanized. Aral's father, Count Piotr Vorkosigan, seeks to abort the fetus rather than have the Vorkosigan name and title passed on to a "deformed mutant," but a furious Cordelia keeps him at bay.
When Count Vidal Vordarian attempts a coup, five-year-old Gregor is rescued by his loyal security chief, Captain Negri, and reunited with the Vorkosigans. Cordelia, Gregor and bodyguard Konstantin Bothari hide from Vordarian's men in the hills, while Aral and his father organize the resistance.
After Cordelia rejoins Aral, they learn that the replicator containing their child, whom they have named Miles, needs periodic maintenance. Without it, the fetus will succumb within six days, but Aral refuses to attempt a rescue when there are far greater concerns. However, Cordelia's personal bodyguard, Ludmilla Droushnakovi, was previously stationed at the palace and knows several top-secret ways to slip inside undetected. Cordelia, Droushnakovi and Bothari set out to rescue Miles and hopefully Gregor's mother, Princess Kareen. When Clement Koudelka, one of Aral's officers, finds out, they kidnap him and persuade him to help out.
In the city, they witness the capture of Lady Alys Vorpatril and the murder of her husband, Padma. They rescue Alys, who is pregnant with Ivan Vorpatril. While in hiding, she delivers her son with Bothari's help. Cordelia dispatches Koudelka to get her to safety and sets out with Bothari and Droushnakovi to get Miles.
Once in the palace, Cordelia and her party are caught in a trap. They manage to overpower their captors, but Princess Kareen is killed. In the ensuing confusion, Bothari sets fire to part of the Imperial Palace to cover their retreat as they take Vordarian himself hostage. When Vordarian defies Cordelia, she orders Bothari to behead him. They escape with the replicator—and Vordarian's head. Cordelia returns to Aral's base and deposits the head on a table in front of some of Vordarian's wavering allies. Without its leader, the coup falls apart.
Miles is born, fragile and deformed. Five years later, he has very brittle bones, but is very active, rambunctious and intelligent, capturing even Piotr's affection.
In a side plot, Koudelka and Droushnakovi fall in love before the coup and indulge in sex at Vorkosigan House. Cordelia, being a liberal-minded Betan, sees no harm in this, but they are ashamed, and a misunderstanding arises. While they are in hiding during the coup, Cordelia acts as a traditional "go-between" to patch up their relationship. After the coup, they marry, and in novels set later, are the parents of four young women who combine brains, beauty and, thanks to their mother's training, unarmed combat skills.
open(ing) the later stage of Bujold's oeuvre, most obviously because of its quantum jump in power, complexity and originality, such as the handling of Bothari, and its excursions into women's territory previously untravelled in SF, but also because it initiates a kind of second, deeper pass over the landscape of the earlier books.[6]
