Sephy is a Cross — a member of the dark-skinned ruling class. Callum is a Nought — a “colourless” member of the underclass who were once slaves to the Crosses. The two have been friends since early childhood, but that’s as far as it can go. In their world, Noughts and Crosses simply don’t mix. Against a background of prejudice and distrust, intensely highlighted by violent terrorist activity, a romance builds between Sephy and Callum — a romance that is to lead both of them into terrible danger. Can they possibly find a way to be together?