Instinct - A Breed Novel, #2

Kyle Singer knew she'd survive the comet with Ichiro, but the knowledge hadn't prepared her for the guilt that came with surviving while the rest of her family had not. After arriving at the school, she discovers that Hartmann had kept track of the families before the comet hit-including Ichiro's missing relatives. Keeping the family's whereabouts a secret, Kyle is determined to find Andy and use their sixth senses to bring her brother back to the school.
To safety. When Ichiro finds out that his family is alive, he goes after them, sending Kyle out on her own. No one knows what they will find venturing out into a world ruined by the comet. Or if they'll be able to return to the school before a second ice age hits.