My Little Brother by Diane Saxon

Two siblings, both missing for 20 years turn up within one day of each other. One dead. One alive. It was an ordinary school day, the day I lost my little brother.
One moment he was on the roundabout and then was gone. Gone. Missing. They all blamed me. I was in charge. Even though I was only ten years old. They sent me away. The hurt, the shame, the questions. The not knowing. I tried to move on. It’s been nineteen years in exile and now somebody wants me back. Someone with a dark secret. They hold the keys, they know the truth. So, I need to return to my childhood village to find out who, because I have a secret, too… I did something bad.