Lady Judith Carew acted furtively on the night of the Denboroughs party. Her secret assignation at 9:30 pm was a meeting to which she took a loaded revolver. The Abbey Court apartment building would play host to violent death that night, under cover of darkness. The killer identity remained a mystery, though Lady Carew had a most compelling motive and her revolver was left in the dead man flat. Enter the tenacious Inspector Furnival in the first of his golden age mysteries.