when a bbc murder thriller be this rife with heterosexual dysfunction and you know who the killer must be represent the homosexual . who murder the sexy blonde teenager ( who also a pathological liar ) on her way home from school . let see and could it be the mother who ( against all common sense ) be let her teenaged son make unchaperoned visit to his serial killer father behind bar . could it be the moody son and who impress by his dad no nonsense attitude about woman . could it be the serial killer himself and who seem able to manipulate event from behind bar and a la hannibal lecter . could it be mom boyfriend and a teacher at the school whose affair with an ex student lead to his wife suicide . or could it be boyfriend daughter and who go blab everyone secret at school and cause untold misery . no and it none of these likely suspect . it . the homosexual . the only mystery for the viewer be guess who the homosexual be . of course and it could be anybody and since the only characteristic of the homosexual be shameful secrecy and a propensity to murder and otherwise make life complicate for the normal folk . the homosexual be the invisible root cause of society ill while only when this person be expose and eliminate can the fracture family come back together and and thing can return to normal . whatever that be . a for the cast and both jemma redgrave and robson green be now officially past their sell by date . the world could get by marvelously without ever see either on screen again and but as long a the bbc have role for the aggrieved woman and the misunderstood man and i suppose they will keep come back in movie like this one .