Friends and traitors : an Inspector Troy novel

"It is 1958. Chief Superintendent Frederick Troy of Scotland Yard, newly promoted after good service during Nikita Khrushchev's visit to Britain, is not looking forward to a Continental trip with his older brother, Rod. Rod was too vain to celebrate being fifty so instead takes his entire family on "the Grand Tour" for his fifty-first birthday: Paris, Siena, Florence, Vienna, Amsterdam. Restaurants, galleries and concert halls. But Frederick Troy...