Amber and Alex meet and track the expanding quakes and volcanic eruptions across New Mexico. Amber's vision of the future terrifies her as she sees the Rio Grande dammed as it begins the process of the great split that will unzip the continent from the Gulf of Mexico to Yellowstone.
Alex faces his first active non-Hawaiian volcano, and his fear of not living up to his father's reputation as a renowned volcanologist. Along the way, his best friend teases him about his interest in Amber, and then leaves to try to convince Alex's dad and his own mom to leave Hawaii. Alex fears they didn't escape, before a massive quake in California sends a tsunami toward Hawaii.
Together, with guides Livia and Corbo, they must gather information so the military can attempt to save as many lives as possible. Amber and Alex grapple with the losing best friends and family, as their world tumbles faster than the Rio Grande swirls.
Although not POV's in this novel - Livia is hurt on Magdalena Peak, and must face her former friends and try to save their lives. She begins to understand what her well-meaning parents tried to do for her, while helping Corbo as he discovers his past is more convoluted than even he thought. As an undocumented illegal immigrant, he is used to blending in, when all he wants is to be part of something bigger. He thinks.