A Million Suns by Beth Revis
(#2 Across the Universe)
When Elder learns harrowing news about the space ship Godspeed, he and Amy must work together to unlock a puzzle that was set in motion hundreds of years earlier, all the while dealing with the romance that’s growing between them and the chaos that threatens to tear them apart. It all boils down to one mind-bending conclusion: They have to get off this ship.
So I liked the first enough book to want to read the second one :). This comes out January 10th,2012!Check out Across the Universe if you haven't!