When Ariane Emory (the first), head of Reseune genetic facilities, is murdered by Jordon Warrick, the next generation at Reseune has their shackles weakened just enough that they might be able to make a difference. Ariane Emory (the second), a replicate of Ariane Emory (the first), grows up in a tightly controlled environment with the hope that she will be just like her predecessor, but things don't work exactly as they hoped, she's starting where Ariane 1 left off, with the skill, instincts, and knowledge, but with the determination to improve upon the legacy of Ariane 1. In particular Ariane 2 wants to make sure that Justin Warrick, Jordon's son and Ariane 1's victim, has the opportunity to achieve his potential and realize his dreams...under her benevolent leadership, of course. When politics don't stop and wait for Ariane 2 to grow up, she must walk a fine line between controlling and being controlled.
In some ways Cyteen is the story of the murder of Ariane Emory, as the cover promises, but it is also much more than that. It is more the story of the ripples in the lives of a handful of people as her death creates a large empty space in the world. It's a story about power: The power that elder's have over youngers; that leaders have over successors; that mentally flexible people have over mentally rigid people; the power that love both gives and takes away.
If all of that sounds like it is complicated and wide-ranging, you'd be correct. It isn't that this couldn't be boiled down to a Hollywood movie plot, it's more that Cherryh builds a level of intrigue and detail that would be ill-served when boiled down.
I highly recommend this book for those that enjoy the complications of space operas, but wish they had a smaller cast.