The Clock Struck One by Fergus Hume

And this was the end of Julian Edermont's high spirits. For twenty years he had dreaded and guarded himself against a violent death; but the moment that the fear had been removed the end came. There was something ironical in the way in which Fate had lulled his suspicions only to smite the surer. One day he had been rejoicing in the thought that the reign of terror was over; the next he lay dead under his own roof-tree, and none knew who had slain him.

They found the body in the study, lying near the desk, which was broken open and terribly damaged. As Meg, the cook, stated, his head was smashed in like a pumpkin, and near by lay the weapon with which the deed had been done -- a Zulu knobkerrie, which had been torn from the decorative weapons of the wall. Dora was an exceptionally brave woman, cool in danger and collected in trouble; but even she felt qualmish to see that revered head all beaten, all splashed with gore. The place was like a shambles. Amid the blood lay a pistol, near to the hand of the dead man, and many papers were scattered about it, tossed in confusion from the bureau.