"The spillway iss about midway in Gatun Dam: its channel has been cut through a hill. You come along the side of this channel right up close to the spillway--close, remember!--and leave the box there. The range of the rays, you know, iss two hundred feet: set them to fire one minute after you leave the box. They will destroy the seven gates of the spillway and also part of the dam and the hydro-electric station. Gatun Lake will then empty itself; the canal will be half drained; the power will be gone--it will take half a year to repair it all. The ZX-1 can fly up to the east coast, thanks to Zenalishin's fumbling--yess; but these American fleets are massed in the Pacific; they will have to go around South America to reach the Atlantic--and that will take weeks. "And in that time the Soviet has crossed the Atlantic uncontested and has paralyzed the heart of America, her eastern states. Ah, it iss magnificent!" * * * * * But Kashtanov's thoughts were elsewhere. Peering hard at the chart, he said: "I have a minute to get clear, eh? Well, I can do that; but won't the water sweeping through from Gatun Lake after the spillway is wrecked catch me?" "No. You run up the hill the spillway channel is cut through; it iss high ground, and the golf course iss on high ground. No one will see you coming or going, naturally, and the box iss not big enough to be noticed at night. The noise of its equalizers will be covered by the water coming through the spillway. It iss--what they say?--fool-proof. You cannot fail, Kashtanov. And--" he broke into swift-flowing, liquid Russian, his swarthy face lighting up, his arms waving, one of them slapping the other's back. "Stop the dramatics," said Kashtanov, "and speak in English. I've worked so long in America, Russian is hard to understand. Time to begin?" Istafiev glanced at a watch on his wrist. "A few minutes. Look you." He went to a side locker in the room, opened it, hauled out with both hands a box of plain dull metal, and put it on the table. It was larger than the one Chris Travers had seen on the ZX-1, but otherwise similar. "A double charge of nitro-lanarline iss in this," murmured Istafiev complacently. "Imagine it, when released! You know the working well, do you not? Yess. Well, I put it in the plane, ready." He stepped to the hut's single door and passed out. Through it Chris could see the tiny clearing, dark under the camouflaged framework, now closed once more; the light from the hut showed him the wings of the helicopter-plane standing there. He heard, moreover, the sound of a shovel from somewhere, and knew that a lonely grave was being dug in the wilderness. Then Istafiev shouted: