The Sky is Falling - Sidney Sheldon

Washington TV anchorwoman Dana Evans (from Best Laid Plans) suspects the accidents befalling the rich Winthrop family, killing all five members, were murders. Like Chicken Little and the sky falling, she chases clues across the world to unravel an international conspiracy. The inheritance goes to charity, so money is not the motive.

Her Sarajevo ward Kemal gets expelled, a prosthetic arm, then often naps afternoons under care of kindly new housekeeper. Unseen agents follow her, bug hotel rooms, while an evil mastermind voice overhears taped conversations and supervises regular secret auctions, inviting armed wealthy customers. Witnesses and informants die before, and after meetings. Friends become foes, nobody can be trusted.