Mysteries of love, romance, and truth-telling lie at the heart of Isabel Dalhousie's concerns in Alexander McCall Smith's new Sunday Philosopher's Club novel. Isabel's niece, Cat, is still worshipped by the young musician, Jamie, but Cat has a new and unsuitable love interest. Meanwhile Isabel's Texan cousins have arrived in Edinburgh and are provoking a quite separate set of dilemmas.

Amateur sleuth Isabel Dalhousie is a philosopher who uses her training to solve unusual mysteries. She edits the Review of Applied Ethics, addressing such questions as "Truth telling in sexual relationships", and she also hosts The Sunday Philosophy Club at her house in Edinburgh. Behind the city's Georgian facades, its moral compasses are spinning with greed, dishonesty, and murderous intent.

Isabel Dalhousie, philosopher and amateur solver of other people's problems, meets an old foe, Minty Auchterlonie, at a birthday party attended by their young children. Ambitious Minty, now the head of a small investment bank, is in trouble with her shareholders. Isabel becomes involved, and is drawn into a murky world of financial concealment.

Isabel Dalhousie thinks often of friends, sometimes of lovers, and on occasion of chocolate. As an Edinburgh philosopher, she is certain of where she stands. She can review a book called In Praise of Sin with panache and conviction, but real life is...well, perhaps a bit more challenging....

For philosophically-minded Isabel Dalhousie, editor of the Review of Applied Ethics, getting through life with a clear conscience requires careful thought. And whilst juggling the arrival of baby Charlie, a passionate relationship with his father Jamie, a truce with her furious niece Cat, and struggles for authority over her son with her formidable housekeeper Grace, Isabel finds herself drawn into the story of a painter's mysterious death off the island of Jura.