First Light by Rebecca Stead.
Peter is very excited to be joining his parents on a scientific trip to Greenland. His father is studying global warming, and his mother is happily joining him to work on her book. While Peter is happy to go, he is also dealing with headaches and strange visions that come out of nowhere.
Thea has never left her home beneath the ice, a place of safety for her people when they fled persecution on the surface. Thea believes that her people need to find a way to the surface, even though her own mother died during a similar search. Now if Thea can only convince others in her community that it is worth the risk.
The two stories of these teens are very different, yet meld into something much more complete when together. The skill of weaving the two worlds together is evident in the balancing; neither story dominates. Skill was also necessary when the two worlds collide and neither story is sacrificed at that point either. Equally important are the twists and turns of the story itself. At some points the reader will think they understand it all, just to have it twisted away from them, creating a very thrilling read. Characterization is strong, with even secondary characters having unique personalities and perspectives. There is a real depth to the story, made even deeper by the presence of global warming, social persecution, and destiny.
Highly recommended, this book offers unique world-building without leaving earth. Should be recommended to teen lovers of both science fiction and fantasy who are ready for some depth that doesn’t compromise the ease of reading.