Ethan is a young man looking to get ahead in life and start a family when his career hits a problem: the fertility clinic where he works is running out of viable eggs. And the obvious solution of asking for or buying new donations is impossible as Athos has no women and is isolationist to boot (we're told that they have religious reasons for this, but the book doesn't go into this). So when the purchase goes wrong (they receive a pile of biological waste instead of eggs) Ethan is sent to proquire replacements. Of course he will be rewarded for this if only he can resist the evil siren call of... women.
Given the gynophobic nature of Athos, naturally the first person Athos runs into is Eli Quinn (on a mission from Miles, though at first we're just told that she's visiting her "Home Planet", Kline Station). After she rescues Ethan from an assassination attempt, she acts as a sort of native guide for the naive Ethan and they are drawn into a world of Cetagandan spies, Jackson Hole enforcers and telepathic agents.
While this is a rather disposable book in the grand sweep of the Vorkosigan series (there is a reference to the goings on here in, I believe, "Cetaganda", but it otherwise has almost zero impact on events elsewhere), it does have some suitably "Bujoldian" touches. Women are referred to (on Athos, at least) as "Uterine Replicators with Legs" and Athos is one of the few planets where childcare costs are fully accounted for (a cynic - especially a female cynic - might comment that when a men have to bear the costs of bringing up a baby, of course they fully account for childcare costs). Kline Station's "Hat" is "terrified of (xeno-)biological infections", which results in a scene where Eli in a suitably "Milesian" moment brings the wrath of Kline Station down on a Cetagandan agent by accusing him of having an STD.
Overall, it'll keep you amused for a couple of hours but isn't exactly a "Must Read".