Peter lives in New York with his parents who are both scientists. His father studies glaciers and global warming and for the first time ever invites Peter to go along on one of his trips to Greenland. Peter is excited to go but he's also worried because he has been having headaches. His mother has suffered from dibilitating headaches his entire life and she has always asked him if he has any. Peter is afraid that if he reveals that he has begun having headaches too his family will not take the trip to Greenland.
Thea lives in the town of Gracehope which is located underneath the ice in Greenland. Her people have lived there for generations after they fled from angry mobs that wanted to harm them for the special abilities some of them possess. Thea believes that it might be time for her people to return to the surface because space and food is getting tight but the elders of Gracehope are violently opposed to this idea. When Thea decides to take matters into her own hands and travels to the surface anyway she accidentally runs into Peter and they find that they have more in common than either could have ever imagined.