In bestselling author Alexander McCall Smith's ninth tale of Isabel Dalhousie, Edinburgh philosopher and sleuth, the victim of an important art theft appeals to her for help.

As a philosopher, mother, employer and resident of Edinburgh - the birthplace of moral philosophy - Isabel Dalhousie is aware that to be human is to be responsible. But morals, it turns out, are rather like clouds: complex, changeable and tricky to get a grip on. As she enters into ransom negotiations over a stolen painting on behalf of wealthy philanthropist Duncan Munrowe, a case where heroes and villains should be obvious turns murky. The list of those who desire the painting - or the money - is long, and hasty judgement must be avoided. Isabel has tact, lively intelligence and a sharp eye, and she'll need them all if she is to see the culprit clearly.

As a mother, wife, employer and editor of the Review of Applied Ethics, Isabel Dalhousie is aware that to be human is to be responsible. So when a neighbour brings her a new and potentially dangerous puzzle to solve, once again Isabel feels she has no option but to shoulder the burden.

A masterpiece painting has been stolen from Duncan Munrowe, old-fashioned philanthropist, father to two discontented children, and a very wealthy man. As Isabel enters into negotiations with the shadowy figures who are in search of a ransom, a case where heroes and villains should be clearly defined turns murky: the list of those who desire the painting - or the money - lengthens, and hasty judgement must be avoided at all cost. Morals, it turns out, are like Scottish clouds: complex, changeable and tricky to get a firm grip on; they require a sharp observational eye, a philosophical mindset, and the habit of kindness. Fortunately for those around her, Isabel Dalhousie is in possession of all three.