A young girl's mutilated body is discovered in a room that has been sealed for the last sixty years. Her remains are carefully arranged in what seems to have been a macabre ritual. For newly appointed Edinburgh Detective Inspector Tony McLean, this baffling cold case ought to be a low priority, but he is haunted by the young victim and her grisly death. Meanwhile, the city is horrified by a series of bloody killings—deaths for which there appears to be neither rhyme nor reason, and which leave Edinburgh's police at a loss. McLean is convinced that these deaths are somehow connected to the terrible ceremonial killing of the girl, all those years ago. It is an irrational theory that will lead McLean closer to the heart of a terrifying and ancient evil. Natural Causes is a chilling and exciting start to a brand new series of mysteries.

Menos de veinticuatro horas después de que un prominente ciudadano de Edimburgo es asesinado, la policía local atrapa al homicida, lo que constituye un triunfo para los representantes de la ley. El hecho de que, poco después, el criminal cometa suicidio no inquieta a nadie; pues la ciudad se ha ahorrado el tiempo y el costo que implica el correspondiente proceso judicial. Sin embargo, poco después ocurre una muerte similar y, también en esta ocasión, el responsable se suicida. Estos hechos llaman la atención del inspector Anthony McLean, quien decide investigar. Muy pronto se da cuenta de que, detrás de estas muertes, puede ocultarse un macabro ritual.