thing except that one," said Terry. "It looks like a message intended only for someone who knew what frequency would make it visible." Underwood shook his head. "That sounds a little too melodramatic for me. Yet it is possible that this thing is some kind of repository, and we've found the key to it. But what a key! It looks as if we've got to decipher the language of the Stroids in order to use the key." "The best men in the field have been trying to do that for only about seventy-five years. If that's what it takes, we may as well quit right now." "You said that this was nothing like any other Stroid characters that you had seen. Maybe this belongs to a different cultural stratum. It might prove easier to crack. Who's the best man in the field on this stuff?" "Dreyer at the semantics lab. He won't touch it any more. He says he's wasted fifteen years of his life on the Stroid inscriptions." "I'll bet he will tackle this, if it's as new as you think it is. I've seen some of those antiquarians before. We'll get Phyfe to transmit some copies of this to him. Who's the next best man?" "Probably Phyfe himself." "It won't be hard to get him started on it, I'll bet." It wasn't. The old scientist was ecstatic over the discovery of the inscriptions upon the huge gem. He took copies of the pictures into his study and spent two full days comparing them with the known records. "It's an entirely new set of characters," he said after completing the preliminary examination. "We already have three sets of characters that seem to be in no way related. This is the fourth." "You sent copies to Dreyer?" "Only because you requested it. Dreyer admitted long ago that he was licked." During the week of Phyfe's study, the work of radiation analysis had been completed. It proved completely negative with the single exception of the 150 A. radiation which rendered visible the characters on the gem. No secondary effects of any significance whatever had been noted. The material reflected almost completely nearly every frequency imposed upon it. Thus, Underwood found himself again at the end of his resources. It was impossible to analyze material that refused to react, which was refractive to every force