He nodded. Mentally I still floundered, but he seemed intensely preoccupied and it was no time for asking questions; so while his words circled unintelligibly in my mind I looked round at the scene before me, glad of the opportunity to recover breath and some measure of composure. But hardly had I time to notice the twisted and contorted shapes of many of the pine trees close at hand when Dr. Silence leaned over and touched me on the shoulder. He pointed down the slope. And the look I saw in his eyes keyed up every nerve in my body to its utmost pitch.

A thin, almost imperceptible column of blue smoke was rising among the trees some twenty yards away at the foot of the mound. It curled up and up, and disappeared from sight among the tangled branches overhead. It was scarcely thicker than the smoke from a small brand of burning wood.

“Protect yourself! Imagine your shell strongly,” whispered the doctor sharply, “and follow me closely.”