The Albert Gate Mystery

The story hinges around priceless imperial diamonds sent by the Sultan of Turkey to London, to be cut in the heavily guarded Albert Gate mansion by experts under the protection of the British government. However, four Turkish officials are found dead in the house, and the diamonds disappear. The leading culprit is Jack Talbot, a young secretary at the Foreign Office who is overseeing the endeavor and also disappeared without a trace the evening of the murders.