Phyfe said, "They were semanticists as well. They knew Carnovan's frequency. It's right here, the key they used to reveal their language. No one less advanced in semantics than our own civilization could have deciphered it, but with a knowledge of Carnovan's frequency, it is simple." "Practically hand-picked us for the job," said Terry. Phyfe's sharp eyes turned upon him suddenly behind the double protection of his spectacles and the transparent helmet of the spacesuit. "Perhaps," said Phyfe. "Perhaps we are. At any rate, there are certain manipulations to be performed which will open this chamber and provide passage to the interior." * * * * * "Where's the door?" said Underwood. Following the notes he had made, Terry moved about the room, directing Underwood's attention to features of the design. Delicately carved, movable levers formed an intricate combination that suddenly released a section of the floor in the exact center of the room. It depressed slowly, then revolved out of the way. For a moment no one spoke while Phyfe moved to the opening and peered down. A stairway of the same glistening material as the walls about them led downward into the depths of the repository. Phyfe stepped down and almost stumbled into the opening. "Watch for those steps," he warned. "They're larger than necessary for human beings." _Giants in those days_ came to Underwood's mind. He tried to vision the creatures who had walked upon this stairway and touched the hand rail that was shoulder high for him. The repository was divided into levels and the stairway ended abruptly as they came to the level below the anteroom. The chamber in which they found themselves was crowded with artifacts of strange shapes and varying sizes. Not a thing of familiar cast greeted them. But opposite the bottom of the stairway was a pedestal and upon it rested a booklike object that proved to be hinged metallic sheets, covered with Stroid III inscriptions, when Terry climbed up to examine it. He was unable to move it, but the metal pages were locked with a simple clasp that responded to his touch. "It looks as if we've got to read our way along," said Terry. "I suppose this will tell us how to get into the next room." Underwood and the other expedition members moved cautiously about, examining the contents of the room. The two photographers began to make an orderly pictorial record of everything within the chamber. Standing alone in one corner, Underwood peered at an object that appeared to be nothing but a series of opaque, polychrome globes tangent to each other and mounted on a pedestal. Whether it were some kind of machine or monument, he could not tell. "You feel it, too," said a sudden quiet voice behind him. Underwood whirled about in surprise. Phyfe was there behind him, his slight figure a shapeless shadow in the spacesuit. "Feel what?"