Who is the girl in the red cardigan?

Sometimes Evie sees things that other people don't. She's wary of the other kids at school, of what they might see in her drawings, or of what they would say if they knew she was different. So most of the time she blocks it all out and pretends she's just like everyone else.

But a missing girl is trying to tell Evie something. A girl who is very persistent, who will not give up until she is found. A girl who once wore the red cardigan Evie now wears. And Evie can no longer ignore the question that needs an answer ... Who is the girl in the red cardigan?