Martin Glass has learned the horrible truth about his 'perfect' existence inside the suburban dome where he has lived for his entire life. He escaped the dome in order to find his little sister who had been 'recalled' by the government. Now he finds himself a fugitive from that same government and he doesn't fit with the group of refugee rebels who are now raising the 'super baby' geniuses, including his sister. He decides that he will have to live on his own in the dangerous outdoors. First though, he has to save his parents. But once outside, they don't understand this new life and they don't understand that he is not a little kid anymore. Can Martin keep his family safe and in the meantime, save the whole world from a government gone terribly wrong? With robot dog Chip by his side, Martin faces danger and some eye opening truths in this sequel to The Sky Inside.