Checkmate — Malorie Blackman

Can the future ever erase the past? Rose has a Cross mother and a Nought father in a society where the pale-skinned Noughts are treated as inferiors and those with dual heritage face a life-long battle against deep-rooted prejudices. Sephy, her mother, has told Rose virtually nothing about her father, but as Rose grows up she becomes determined to find out more about her parentage. As Rose takes her first steps away from Sephy and into her father's world, she finds herself drawn inexorably into danger.