Alexander McCall Smith 
The Charming Quirks Of Others 

As well as its advantages, there are drawbacks to the enlightened village that is twenty-first-century Edinburgh, where every Saturday night ears burn at dinner parties across the city, and anyone requiring the investigative abilities of a philosophical soul knows where to find her.
Jillian Mc Kinlay — wife of a trustee of an illustrious school — is the latest petitioner; she asks Isabel to look into a poison-pen letter that makes insinuations about applicants for the position of principal. Isabel”s niece Cat has another new boyfriend who seems too good to be true. And when a pretty cellist with a tragic story takes a fancy to her husband-to-be, Isabel finds herself contemplating an act of heroic and alarming self-sacrifice.