Margaret Peterson Haddix knows how to make me feel for the characters. She did this pretty well in the first book (Among the Hidden), and she does it again in this second book in the Shadow Children series. Among the Imposters once again follows Luke as one of the Shadow Children, those third (or fourth, or however many) children that were not supposed to be conceived, let alone born. I sympathized with his confusion and despair in his attempt to adapt to the environment he is thrust into. That being said, we spent a lot more time in Luke's head and his imagined responses to situations than I would have preferred. I kept reading these responses, thinking, wait - did he actually do that? No, that was just what he thought about doing. Sometimes this caused me to have to read passages over again, just to make certain I knew what actually happened.
Since this is really a continuation of the first book's story, I wouldn't recommend reading them out of order.
A few twists and turns, and I am looking forward to the third.