For a moment the blood congealed around his heart, and he clutched at the desk to support himself.

The corn operator was about to relock the steel door.

It was now or never if he was to do anything.

Without waiting for the fiendish suggestion to cool he seized a heavy ruler and, with a muttered imprecation, sprang at the operator from behind.

Mr. Whitemore heard him and gave a startled glance backward.

But he was at the infuriated man’s mercy.

Thud!

The ruler descended on the old operator’s head, and he went down on the carpet like a stricken ox at the shambles.

At that identical instant Vance Thornton, dusty and travel-stained, appeared at the office door.

He was a witness of the murderous attack.