A sharp cry escaped Rupert’s lips. He bent down and examined the black, sticky substance more carefully. "It is pitch-blende!" "Extinguish the light," Despard said sharply. Rupert obeyed. A long time they stood in the darkness. Presently Despard commenced to dig and scrape the surface and sides of the tunnel. After a little while he struck a match and re-lit the lantern. "That was expecting rather too much," he whispered. They collected the pitch-blende they had found, and putting it into his handkerchief Despard dropped it into his pocket. "I’ll examine this and test it to-night. But don’t say anything about it, not even to your father. Just because we’ve found pitch-blende it doesn’t mean there’s radium. But—they have found traces in some of the Cornish mines, you know." Marjorie was waiting for them at the surface of the mine. She gave a shriek as she saw them, for their clothes were torn and discoloured, and they were wet through. "Well, how much tin did you find?" she asked jokingly. "Are you going to make our fortunes?" Despard looked at her. "Supposing I were to make a fortune for you, what reward should I get?" "Oh, fifty per cent. of the profits," she laughed, lowering her eyes. "I shouldn’t ask that," he whispered. "I should want something money couldn’t buy." When they reached the farmhouse supper was waiting. It was growing dark, and work was over for the day. John Dale had not returned home. "We had better wait," Marjorie suggested, "He’s never late. Probably he has gone up to Post Bridge Hall to see Sir Reginald Crichton on business." The mention of Reginald Crichton’s name reminded Rupert of what his father had told him about having to mortgage the property. Supposing there was anything in their discovery that afternoon the mortgage would have to be paid off before anything else was done. He went up to Despard’s room and suggested that while they were waiting for supper they should examine the sample of pitch-blende they had taken from the mine. Despard locked the door and laid the mass of putty-like substance on the table. "To get a proper test we ought to take or send it up to town," he said. "But there’s one simple method——" He was interrupted by Marjorie calling to Rupert. "You’re wanted at Post Bridge Hall at once," she told him. "Father is there, and they’ve sent a servant over to ask you to go up." Rupert swore under his breath. "What on earth can the matter be? You don’t think anything has happened to—the old man?" Marjorie shook her head. "I don’t think so. The message is simply that you’re wanted."