In the societal turmoil of 1984, when the heiress to an oil fortune Catriona Grant is kidnapped at gunpoint and held to ransom with her young son, Adam, it's assumed that the motivation is political. The huge investigation ignited an uncontrollable press storm but when the culprits unexpectedly fall silent, the case runs cold. Catriona and Adam are never seen again. Forty years later, when a man's body is discovered, Karen Pirie is assigned to reopen the case in complete secrecy. With the first key piece of evidence in decades, Karen and the team wade through a history of love, deceit, political unrest, and class struggle in order to unlock one of Scotland's most infamous mysteries, whilst avoiding media attention. What happened to Catriona Grant and why do sinister forces want the secrets of her disappearance to remain hidden?