Cassie and the remains of humanity live on an immense space station, taken from earth when environmental disaster wipes out the population. At least that what she's always been told...with the help of her friend (and then boyfriend) Balik, Cassie explores the dark secret behind Space Station Hope, a revelation that eventually leads her fleeing for her life.Although the book was a little slow to get started, I didn't feel like I wanted to put it down at any point. Mel C-J created a believable world, and one which kept me guessing right up to the last chapter.Some theories I was flicking through as I was reading included Nineteen-Eighty-Four, Logan's Run, Soylent Green...Was it even a space station, I wondered? All of these theories were way off the mark, and close to the end, I wondered if Cassie's parents were androids, and all of what was happening was benign. Wrong again!The idea of a space station run by aliens so they can harvest human DNA was done with subtle hints and misdirection. At no point did I guess that was what was happening on the station. In some places, the editing was a little rushed, and because of that, some of the nice ideas in the book slipped past me. I was too busy trying to figure out the sentence to concentrate on the story. Mel C-J did seem to need more commas so I could get a sense of what's going on.That was particularly bad near the end of the book, when Cassie's father showed up. I think the scenes with him could have been cleaned up quite a bit. I also think a bit more world building to establish the scale of the space station would have helped, and I would have liked to have seen more of the guts of the place, as it were.I liked all the characters in the book, even breathless Ami and Olivia, who shows her humanity later in the book despite her superficial appearance and personality. Everyone was well rounded and nicely developed. I even felt empathy for the aliens, forced to harvest humans to survive.In the end, I'd give it 4/5, mainly dropping the star for the grammar errors that needed fixing. But I'm hooked enough to start looking for the sequel!