Cooper Klavan and his sister, Anna, are fishing with their parents at a woodland pond when they come across an injured bird. Anna, a huge animal lover, insists on taking it home to rehabilitate. But the bird really does not want to be rescued. It bites Anna. Soon, she is behaving very strangely: perching high up in trees and gathering sticks to hide in her room. Cooper doesn't want to jump to any conclusions, but his sister seems to be going to the birds.