"We ran the dates and times of sightings through the computer with a lot of other dates and times for various things," Steve explained. "I had a hunch, but the computer turned it into good comparative data." "What data?" Scotty demanded. "Every single sighting you collected coincided with the launching of a research rocket from Wallops Island!" The boys sat back, openmouthed. Rick said, "So that's why the glow from Wallops Island in the south-eastern sky was so significant. That's what put you on the trail!" "Right," Steve agreed. "The yellow glow is from sodium vapor rockets fired from Wallops. The rockets allow visual measurement of meteorological data. People around here are used to seeing them to the southeast, over Wallops. When I saw that sightings had been made over Swamp Creek at the time of sodium shots, I got an idea. It wasn't much to go on, but it was at least a good clue. The computer did the rest." "Then Lefty Camillion and his friends have been intercepting data from our rocket launchings at Wallops," Scotty said unbelievingly. "But why? How could Lefty use data like that? It's all straight, unclassified scientific and meteorological stuff. He's no scientist." Steve grinned. "I doubt that he even knows what the data are. He and his friends are a bunch of chuckleheads of the very worst kind. But about what he does with the data--Joe Vitalli has been doing some investigating along that line." Vitalli nodded. "With the FBI. They put agents on the case and found out Lefty had been in touch with the Soviet Embassy in Washington, through a third secretary whose function it is to gather various kinds of scientific intelligence. We're not absolutely certain, but it looks very much as though Lefty plans to sell his data tapes to the Soviets." "So that's why JANIG has moved into the case," Scotty concluded. "On the nose," Steve agreed. "Now it's time to move in on our foolish friends at Calvert's Favor. Do you boys want to take a hand?" "Try and leave us out," Rick said with a grin. "JANIG is welcome to assist us, but the flying stingarees are our babies. Scotty's and mine, that is." "Be glad to have you help," Scotty echoed. The JANIG men laughed. "You've got a point," Chuck Howard conceded. "Want to plan the operation?" Steve asked with a twinkle. Rick held up his hand. "Whoa! We didn't say that. You've got information we don't have." "Only one piece of information," Steve replied. "The time of the next launching from Wallops Island." "When?" Rick asked eagerly. "At dusk tonight." CHAPTER XVIII The Stingaree's Tail "This is the plan," Steve Ames said. "Joe and Chuck will approach from upriver and go around the mansion fence by wading downstream. They'll stay under cover somewhere at the edge of the mansion grounds until they hear my signal on the radio to close in--or until they see the balloon launched. I'll go in the way I did before."