His mouth was open, his eyes staring, and upon his face such a look of sheer terror was stamped as Thresk could never find words to describe.

For the first moment he imagined that the man had had a stroke.
His habits, his heavy build all pointed that way.

The act of stooping would quite naturally be the breaking pressure upon that overcharged brain.

But before Thresk had risen to make sure Ballantyne moved an arm.
He moved it upwards without changing his attitude in any other way, or even the direction of his eyes, and he groped along the flap of the bureau very cautiously and secretly and up again to the top ledge.

All the while his eyes were staring intently, but with the intentness of extreme fear, not at the despatch-box but at the space of carpet--a couple of feet at the most--between the despatch-box and the tent-wall.
His fingers felt along the ledge of the bureau and closed with a silent grip upon the handle of the riding-crop.