The Death Watch Ladies — John Newton Chance

The detective had only to find an uncle who had gone missing, and whose hat had been found. But when he arrived at the house of the van Deken family, his ideas of an easy job vanished. He was beset by each member of the family taking him aside to tell a different story of what had happened, and which incriminated another member of the family. Before long the detective didn't know quite who was dead, missing, or about to be dead!