"There's the Secret Service," I thought. "They are skilled in reading hidden messages. It must be an important one, worthy of the efforts of the Secret Service, or he would not have been at such pains to get it to me-- "But no. The Secret Service is skilled at reading hidden messages, but not as skilled as I am in reading my friend's mind. Knowing Benda, his clear intellect, his logical methods, will be of more service in solving this than all the experts of the Secret Service." I barely stopped to eat dinner when I reached home. I hurried to the laboratory building, and laid out the specimens on white sheets of paper, meticulously preserving order, position, and spacing. To be on the safe side I had them photographed, asking the photographer to vary the scale of his pictures so that all of the final figures would be approximately the same size. Plate I. shows what I had. * * * * * I was all a-tremble when the mounted photographs were handed to me. The first thing I did was to number the specimens, giving each blank space also its consecutive number. Certainly no one could imagine a more meaningless jumble of twigs, leaves, berries, and bugs. How could I read any message out of that? Yet I had no doubt that the message concerned something of far more importance than Benda's own safety. He had moved in this matter with astonishing skill and breathless caution; yet I knew him to be reckless to the extreme where only his own skill was concerned. I couldn't even imagine his going to this elaborate risk merely on account of Smith and Francisco. Something bigger must be involved. I stared at the rows of specimens. "Communication is a science!" Benda had said, and it came back to me as I studied the bent worms and the beetles with two legs missing. I was confident that the solution would be simple. Once the key idea occurred to me I knew I should find the whole thing astonishingly direct and systematic. For a moment I tried to attach some sort of heiroglyphic significance to the specimen forms; in the writing of the American Indians, a wavy line meant water, an inverted V meant a wigwam. But, I discarded that idea in a moment. Benda's mind did not work along the paths of symbolism. It would have to be something mathematical, rigidly logical, leaving no room for guess-work. No sooner had the key-idea occurred to me than the basic conception underlying all these rows of twigs and bugs suddenly flashed into clear meaning before me. The simplicity of it took my breath away. "I knew it!" I said aloud, though I was alone. "Very simple." I was prepared for the fact that each one of the specimens represented a letter of the alphabet. If nothing else, their number indicated that. Now I could see, so clearly that the photographs shouted at me, that each specimen consisted of an upright stem, and from this middle stem projected side-arms to the right and to the left, and in various vertical locations on each side.