Scotty added, "Today, when we got to the station, I took a look along the trail. There's only one bend in it. If he was keeping a watch at the bend, he could have seen us arrive at the second station, hurried down the trail, set off the charge, then returned through the jungle to get his jeep." "But the fact that he could have, does not mean that he did," Hartson Brant stated. "We can't prove it," Scotty agreed. Rick continued. "Then we trailed him to Casa Guevara. He couldn't have been paying a social call, because he wasn't there long enough. And what business does he have with Guevara? I don't know, but I'll bet his business is the reason we can't get Guevara to move." "Possibly," Hartson Brant agreed. "I can see the reason for your suspicions, but you lack proof of anything, Rick. What motive could Connel have?" "We hoped to find out at the shot station," Rick replied. "But we drew a blank." Dr. David Riddle came into the room and joined them. Before anyone could speak, the geologist spotted the samples on the table and sucked in his breath sharply. "Where did these come from?" he demanded. "Connel's third shot station," Rick replied. "Do you know what the stuff is?" Riddle sank into a chair and picked up one of the samples, testing it between his fingers. "Yes," he said, "I do. I've seen it only once before, in Africa. It occurs in what is known as a volcanic pipe, actually an ancient channel that gets filled with the stuff for reasons we do not know." "A volcanic pipe," Hartson Brant said softly. "I'm beginning to see." Rick wasn't. "But what is it?" he asked. "The most valuable kind of ground in the world," Riddle said. "So far as anyone knew up to now, such pipes have occurred only in Africa. The one I saw was at Kimberley. The name came from there. This is kimberlite." [Illustration] Rick knew of only one kind of valuable that was associated with Kimberley, and the thought was so staggering that he was almost afraid to say it out loud. "You mean that this is the stuff diamonds are found in?" "Exactly," Riddle said. Rick fished the handful of crystals from his pocket and stared at them unbelievingly. "Then these," he said hoarsely, "must be diamonds!" CHAPTER XI Earthquake! "Everything adds up," Rick Brant said grimly. "And it isn't a pretty picture." Hartson Brant agreed. "It certainly seems to add up, Rick. I suggest you put those crystals in a safe place until we can find out for certain whether or not there is real value there." "Is there any doubt?" Scotty asked. David Riddle answered, "Yes, Scotty. There are many grades of diamonds. Until an expert takes a look at those Rick collected, we won't be sure that they're of gem quality. He may have industrial grade diamonds, of the type called bort." "Connel may already have had an expert take a look," Weiss pointed out.