The scientist nodded assent. "I'll be glad to. As I told you on the way over, two of our staff members are missing. You know one of them--Dr. Anthony Briotti. The other is Dr. Howard Shannon, our zoologist. Tony, of course, is an archaeologist. They departed for the Sulu Sea several weeks ago on a joint expedition to try to find new evidence for a theory of migration of the early peoples in the Pacific." Hobart Zircon added, "We started on this theory some time ago with a trip to an island in the western Pacific. Dr. Briotti continued that work during the rice-terrace expedition. I believe you met him then." "I did," Colonel Rojas agreed. "How is the present expedition connected with your previous work? The combination of an archaeologist and a zoologist seems unusual." "Tony has determined that the origins of the Bajaus, the Sea Gypsies of Sulu, may be of importance," Hartson Brant explained. "In addition, he wanted to check some details of Bagobo culture. Dr. Shannon hoped to contribute some evidence based on the early migration of some animals from the Asia mainland to the islands." Colonel Rojas nodded. "I understand. The presence of some animals may show that a land bridge existed between Sulu and the mainland across which the early peoples may have migrated." "Exactly. I'm sure you also know that our staff has been co-operating with Dr. Remedios Okola of the University of the Philippines. It was from him we learned that our friends had vanished, when they failed to keep an important appointment." "You know their itinerary?" "Yes. They flew to Manila and spent a few days with Dr. Okola. At that time he persuaded them to revise their schedule, to return to Manila long enough to join him on a trip to the rice terraces. They flew to Zamboanga, chartered a boat of some sort, and sailed to Davao by way of Cotabato. They were supposed to leave the boat at Davao and fly back to Manila to take the trip with Okola, after which they would return to Davao, pick up the boat, and go into the Sulu Sea." The scientist's lips tightened, then he added, "They never kept the appointment with Okola!" "What did Okola do about it?" "He got in touch with the constabulary and asked for a check on their whereabouts, thinking they might have been delayed. The constabulary at Davao reported that Shannon and Briotti had reached Davao and hired a truck to take them to a Bagobo village. The truck driver let them off at a foot trail to the village. No one has seen them since." Rojas rubbed his chin thoughtfully. "You have heard from the American consulate at Manila?" "Yes, by phone, on the same day I talked with Okola. The consulate has asked your government for help. However, yesterday I received a cable stating that a second investigation has uncovered nothing new. It appears that both our governments have done all they can, but obviously we cannot stop there. So I have decided to send Dr. Zircon, with Rick and Scotty, to hunt for our friends."