The officer had theories. Perhaps revolutionaries had stolen it. Also, although it was against the law and brought severe punishment, fishermen were known to dynamite fish. This also was a possibility. But the explosion of the dynamite on the mountainside was certainly a puzzle. Rick didn't think so, but he agreed politely. It was bewildering, he said. Why steal explosives and then use it on a harmless scientific group? Perhaps fear of discovery caused the thief to set a trap, the officer guessed. He admitted it wasn't a good guess. A jeep roared into life and the boys stiffened. The officer strolled out of the shadow for a look. "One of your associates is going for a ride," he said. Rick waited until the jeep lights cut across the parking lot and moved down the western road, then he said, "It's a nice night for a ride, Scotty. What say we take a jeep and look over the country, too?" "Good idea," Scotty agreed readily. They bade the officer good night and started to where Zircon's jeep was parked. It was a temptation to hurry, but they suppressed it and sauntered to the jeep. Fortunately, no keys were needed. The jeep ignition was turned on by a simple switch. Rick got into the driver's seat and started up. He waited, the motor idling, until he was sure Connel was out of sight around the mountain, then he drove slowly across the parking lot and followed. Fortunately, there was enough moonlight to see the road. Once out of sight of the hotel, Rick stopped and switched off the lights. As his eyes adjusted to the dimness he started off again as fast as vision allowed. Once he sighted Connel's lights. They were ahead and higher on the mountain. He lost sight of them again as foliage blocked the view. "Suppose he's heading for the shot station?" he asked. Scotty shrugged. "We'll soon know." They reached the pumice works without seeing the geologist's lights again, and Rick stopped at the turnoff. "Now what?" he asked. "Did he go up the trail or not?" Scotty sniffed the air. "Smell anything?" Rick breathed deeply. There was the odor of rank vegetation, and, very faintly, the odor of sulfur from the hot springs. But there was another smell, too. After a moment he identified it. "Dust!" "Seems so," Scotty agreed. "Which means he didn't take the trail to the stations. No dust on those tracks. He must have taken the dirt road to San Souci." "But why?" Rick was already moving ahead to where the pavement ended. "What's in San Souci?" Scotty chuckled. "Ask Connel. Don't ask me." "I thought Marines knew everything," Rick gibed. "Almost everything," Scotty corrected. The jeep moved onto the dirt road and in a moment their own cloud of dust obscured any slight haze that Connel's passing might have left. They were in strange territory now, and Rick slowed down somewhat. Connel had the advantage of lights. They wouldn't be able to gain on him.