So I told him the story. "Years ago I worked in one of the electrical laboratories where these beams were being developed. One day I was accidentally locked in the testing room--a small chamber where the beams were projected upon metal plates to test their intensity. Luckily for me, the beams that day were of a very low intensity, or I wouldn't be here now. But the power kept increasing by slow degrees, until I could feel the vibration tearing through every fiber of my body. At last, and just in time, I managed to attract attention. I was violently ill for weeks. But after that, I seemed to be hyper-sensitive to such beams." Wilkinson continued digging at the rock with a small metal implement. Bit by bit the rock came out, in powdery dust and tiny chunks. I noticed that his hands were scarred and roughened from day after day of this work. "When we first began," he explained, "we made much faster progress. But now a man can't work more than two or three hours up here, for the air gets pretty stale. We take turns, of course, day after day. It's going to be pretty tough on you from now to the finish, because you'll have to be up here _every_ day for a couple of hours. We're counting on you." Yes, they were counting on me. Now for the first time I began to realize how much; and I began to doubt myself. I wasn't really sure that I could still detect those finder beams. It had been a long time since I had experienced it. Besides, the radite ore emanations had effected my body in that curious tingling way, just as it had every man here. So perhaps that would prevent--? I only knew that if we ever blundered into one of those directional finder beams, which McGowan said were raying down, it would instantly set off an alarm in Marnick's quarters. I tried not to imagine what would happen after that. In a sort of panic I pressed my sweating body against the rocky wall, but all I could feel was the familiar radite-tingling crawling through my skin. * * * * * So we worked day after day until they lengthened into weeks. My daily labor at the radite vein was almost a pleasure now as I anticipated the few hours of work that would come later in our secret tunnel. Daily I accompanied a different one of our group. I wanted to take my own turn at the digging, but McGowan wouldn't stand for this, preferring that I direct all my attention toward the detector beams. Weeks passed and still I detected no beams. Kueelo, I found, was sullen and silent. The other Martian, V'Narik, talked to me only on a few occasions. "I have a curious presentiment," he told me once, "that I shall never escape from here. You others, perhaps, but not me. I am with you on this only because there is nothing better to do. But if I can only reach the surface, and glimpse the stars once again--especially the redness of Mars--this will have been worth while."