The War Orphan by Rachel Anderson
When Ha arrives as part of Simon's family, the nightmares arrive too. And as Simon tries to find out about Ha and his past, he begins to uncover a war-story which is not the one he wanted to hear. Is the story Simon hears in his head his own, or does it belong to this child who his parents now say is his brother - Ha, the war orphan? This novel with a background in the Vietnam War is now being reissued in a smaller, mass-market paperback format. Rachel Anderson is a previous winner of the Guardian Children's Fiction Award.