But Thresk's eyes were keen.

The space between the despatch-box and the wall was empty.

Nothing crawled there, nothing was coiled.
Thresk looked at Ballantyne with amazement; and as he looked Ballantyne sprang from his chair with a scream of terror--the scream of a panic-stricken child.

He sprang with an agility which Thresk would never have believed possible in a man of so gross a build.

He leapt into the air and with his crop he struck savagely once, twice and thrice at the floor between the wall and the box.