“Why, it is nearly one,” he exclaimed. “Yes, a taxi by all means, please.”

Though Inspector French had said that everything possible had been done that night, he did not follow Mr. Duke from the building. Instead, he returned to the inner office and set himself unhurriedly to make a further and more thorough examination of its contents.

He began with the key of the safe. Removing it by the shank with a pair of special pincers, he tested the handle for finger prints, but without success. Looking then at the other end, a slight roughness on one of the wards attracted his attention, and on scrutinising it with his lens, a series of fine parallel scratches was revealed on all the surfaces. “So that’s it, is it?” he said to himself complacently. “Manufacturers don’t leave keys of valuable safes half finished. This one has been cut with a file, and probably,”—he again scrutinised the workmanship—“by an amateur at that. And according to this man Duke, old Gething was the only one that had the handling of the key—that could have taken a wax impression. Well, well; we shall see.”

He locked the safe, dropped the key into his pocket, and turned to the fireplace, soliloquising the while.

The fire had still been glowing red when the crime was discovered shortly after ten o’clock. That meant, of course, that it had been deliberately stoked up, because the fire in the outer office was cold and dead. Some one, therefore, had intended to spend a considerable time in the office. Who could it have been?

As far as French could see, no one but Gething. But if Gething were going to commit the robbery—a matter of perhaps ten minutes at the outside—he would not have required a fire. No, this looked as if there really was some business to be done, something that would take time to carry through. But then, if so, why had Gething not consulted Mr. Duke? French noted the point, to be considered further in the light of future discoveries.

But as to the identity of the person who had built up the fire there should be no doubt. Finger prints again! The coal shovel had a smooth, varnished wooden handle, admirably suited for records, and a short test with the white powder revealed thereon an excellent impression of a right thumb.

The poker next received attention, and here French made his second discovery. Picking it up with the pincers in the same careful way in which he had handled the key, he noticed on the handle a dark brown stain. Beside this stain, and sticking to the metal, was a single white hair.

That he held in his hand the instrument with which the crime was committed seemed certain, and he eagerly tested the other end for prints. But this time he was baffled. Nothing showed at the places where finger marks might have been expected. It looked as if the murderer had worn gloves or had rubbed the handle clean, and he noted that either alternative postulated a cold-blooded criminal and a calculated crime.

He continued his laborious search of the room, but without finding anything else which interested him. Finally, while his men were photographing the prints he had discovered, he sat down in the leather-covered arm-chair and considered what he had learned.