The Balloon Man by Charlotte MacLeod
Art detective Max Bittersohn knows when to lie low. He wisely keeps out of the way when his wife, Sarah Kelling, plans a huge wedding for his nephew at their Boston North Shore mansion. By the time the Kelling and Bittersohn clans arrive on the big day, everything, including the weather, seems perfect. But even Sarah can't foresee a hot air balloon landing on the wedding tent - or the squashed corpse beneath it. And no one anticipates one of the biggest surprises in the Kelling family history: the mysterious reappearance among the wedding gifts of the long-lost Kelling rubies. No believer in coincidence, Max soon rises to the challenge of tying the events together. Meanwhile Sarah's psychic cousin Theonia is seeing visions in her tea leaves, which may prove uncannily accurate ... or a red herring among the orange Pekoe. Then Max vanishes into thin air. Soon Sarah is rallying kith and kin to search for him, while danger descends on their three-year-old son, Davy - in one of the best Charlotte MacLeod mysteries ever.