When the poisoned body of Sir Robert Appleton's steward is discovered amidst the tasteful splendor of Appleton Manor's dining room, the genteel household is thrown into an uproar. Left behind at the sweeping ancestral estate while her husband embarks on a political mission for the new queen, Susanna, Lady Appleton takes it upon herself to investigate what she alone believes to be a cold-blooded murder. An expert herbalist, Susanna sets out to identify the deadly poison that killed the crusty old man - and to unmask a cunning killer bent on striking again...