Harwich snapped on his helmet radio-phone. Young Arnold's voice was already audible in it, faint and thready and sarcastic.

"Well, here we are, Evan," he was saying. "The first Earthmen to set foot alive on the Enchanted World! I guess I got part of what I wanted anyway, didn't I? But with what equipment we've got to keep alive with, we might just as well be buried with the RQ257! Funny I'm not scared. I guess I don't realize...."

His bitterly humorous tone faded away in vague awe.

Still lying prone the two men, looked around them, at the hellish, utterly desolate scene. The hills brooded there under the blue-black sky and tenuous, heatless sunshine. A rock loomed up from a heap of sand. It was a weathered monolith with weird carvings on it, resembling closely those left by the extinct peoples of Ganymede, that other, now colonized moon of Jupiter. A curious pulpy shrub, ugly and weird, grew beside the monolith. A scanty breath of breeze stirred up a little ripple of dust.

That and the stillness. The stillness of a tomb. Harwich could hear the muted rustle of the pulses in his head. Everything here seemed to emphasize the plain facts. The Forbidden Moon was a trap to them now. A pit from which they could expect no rescue. An abyss that was worse than the worst dungeon—worse than being literally buried alive!

It was like the end of things. Was this the kind of slow, creeping, maddening death that George Bayley, the treacherous printer, had planned for them?

Again fury steadied Evan Harwich's determination. Grimly he struggled to steady his nerves.

"Listen, Paul," he said quietly into his phones. "We mustn't ever let ourselves think we're licked! That's sure poison! The stuff we've got in our emergency packs will enable us to keep living for a while anyhow. We know Bayley'll come to Io sometime, with a ship fitted out with a new Penetrator. We know he'll be looking for the secret of the force aura of the Forbidden Moon, and whatever else there is to find. Maybe we can get ahead of him yet, if we keep on the move. Which way do you suppose would be best to go?"

Harwich asked this question because Paul Arnold, in his more academic study of Io, should know more about its terrain than he.

"You know the Tower?" Paul Arnold questioned. "The queer pinnacle, or ruin, or building, near the equator, on what is known as the Western Hemisphere? You must have seen it often when you were on patrol."