We gave this book to Pun Daughter for Christmas. It looked intriguing enough that I asked to borrow it once she was done reading it. The dust jacket featured glowing blurbs from Joss Whedon and io9. And it's good, albeit not quite what I expected. (I expected something like The Hunger Games. Nope, not quite.)
I will try to avoid spoilers here: Melanie is a smart kid in an unusual situation: she goes to school with her classmates, but that involves a couple of armed soldiers coming to get her in her cell. One holds a gun on her while the other puts her into a wheelchair with strong restraints on her arms, legs, and head.
Melanie likes school, though, especially her sympathetic teacher, Miss Justineau. One of the things she learns about is the Pandora myth, whence the title; you'll want to keep an eye on that.
It gradually becomes clear that all is not well in the world outside Melanie's prison. Her teachers drop hints about devastating events twenty years in the past, and it's clear that only a remnant of humanity is carrying on civilization. And Melanie is part of a research project that is humanity's last desperate hope to survive.
Unfortunately, "humanity" pretty much views Melanie as one of the eggs that might need to be broken to make that particular omelet.
The book turns out to be (again trying to avoid spoilers) part of a certain well-known genre, distinctive because there's a gloss of scientific mumbo-jumbo backing things up, something the genre often lacks. It's well-written; the author, M.R. (Mike) Carey had previously made his name mostly writing comic books. And (spoilers at the link) it's going to be a movie with Glenn Close.