A dedicated herbalist, Susanna is caught up in visions of blooming borange and lavender on a sun-splashed June morning until a striking woman draped in mourning black appears bearing a cryptic message for Sir Robert Appleton. Hours later, the stranger is found murdered amidst the beggars and prostitutes of nearby Southwark with a single goosefeather - the killer's curious calling card - lying beside her corpse. As Susanna's investigation takes her from seedy tenements and brothels to the glorious scented gardens of Whitehall Palace, she discovers a trail of victims slain in a similar fashion and a shocking list of possible culprits that leaves few above suspicion - least of all, her own husband...