"It must be important," Jan commented. "The whole staff hasn't been together since Christmas." Rick nodded. That had been a social occasion, not business, and on the day after Christmas he, Scotty, and Dr. Parnell Winston had taken off for Cairo where they had become involved in intrigue and a major scientific mystery. The episode was now referred to as _The Egyptian Cat Mystery_. The boy wondered if this meeting was a beginning of something exciting, too, and in the same instant he was sure that it was. "Here comes Barby," Jan said suddenly. "Excuse me, Rick." Barby Brant, Rick's pretty blond sister, paused in the doorway until she saw Jan hurrying to meet her. The two girls conferred briefly, then hurried to take seats in the exact center of the front row. It was the custom at Spindrift to include the island's young people in staff activities, and Rick had been a part of the various projects and discussions since he could remember. But not until Jan Miller's arrival on the island, during the adventure of _The Electronic Mind Reader_, had Barby bothered to attend the scientific discussions. Jan, as bright as she was attractive, had succeeded in persuading Rick's sister that science was not only exciting, but understandable. The buzz of talk in the room stopped as Hartson Brant and his guest entered, followed by Scotty. The husky, dark-haired ex-Marine at once joined Rick. The two had been close friends and constant companions since the day Scotty joined the staff during _The Rocket's Shadow_ project. An orphan, Scotty was now a permanent member of the Spindrift family. Hartson Brant did not need to rap for attention. There was an expectant hush as he began immediately. "Our guest today is Dr. Esteben Balgos, of whom many of you have heard. Until his retirement a few years ago, he was considered by his colleagues as the dean of South American geophysicists. His primary field of interest was--and still is--volcanology." Rick leaned forward. Volcanology, study of volcanoes. The mountain that formed the backbone of San Luz had once been a volcano, but it had been dead or inactive since prehistoric times. El Viejo--the Old One--was its name. Rick wondered if it might not be the connecting link between San Luz and Spindrift, but he couldn't yet see how. "Dr. Balgos reached me at Florida University while I was lecturing there. We talked, and I agreed that we would examine his problem. It is so unusual and challenging that I wanted all of you to hear what he has to say. Rick and Scotty have built a scale model of the island to help Dr. Balgos describe the problem to us." "So that's why we built it," Scotty whispered. "I've been wondering." Rick grinned. So had he. Dr. Balgos acknowledged Hartson Brant's introduction, took a moment to wipe his horn-rimmed spectacles, and got down to business, using a pencil as a pointer. He spoke perfect English with a soft, musical Spanish accent which Rick found pleasant.