The Prime Minister has been murdered. Whilst under police protection at Chequers, their official country residence, his widow, Helen Cosgrave, discovers her husband's private and damning bank statements. Samantha Quest knows the late Prime Minister's secrets and at considerable risk to herself, she agrees to talk to Helen Cosgrave. As a virtual prisoner in the house she enlists Quest to contact the person her husband has been secretly paying. When there are more deaths and a prostitute is reported missing the situation begins to threaten the private lives of politicians and their weaknesses...