Known the world over for his No. 1 Ladies' Detective Agency series, Alexander McCall Smith is also the author of the much-loved Isabel Dalhousie mysteries. In 'Sweet Thoughtful Valentine,' Isabel faces a moral dilemma after she learns a delicate secret. Entrusted with the intimate details of a former classmate's collapsing marriage, Isabel finds herself in the awful position of having to betray a trust. With the weight of her moral obligation bearing down, Isabel must rely on her considerable wit and the guidance of her devoted husband to save the day.