The neural connection between Kayla and her dog seems unimportant, until her father's cryptic message.
Your mother and I are in danger, and I'm afraid that means you are too. I've gone into hiding. Don't try to find me unless I contact you, and don't let Saffi find me. You and Saffi should go too. Go and hide together.
Kayla doesn't really trust her father. After all, he left her mother and dragged Kayla off to live in the country. And when Kayla's mother gave her Saffi, her father somehow won the dog's loyalty.
But Kayla can't reach her mother. She has to decide, on her own, what to do. Should she hide in the forest with Saffi? Should she try to find her father? And what danger threatens?