"Triangulation" simply meant the drawing of straight lines on a chart from two different points of reception toward the source of the signal. The intersection of the straight lines indicated the location of the transmitter.
"So what they're going to do to reduce the odds of getting caught," Canidy said, "is to go on the air as little as possible. The first signal we'll listen for when we get close enough will be on the air for only five minutes. Then it will go off and come back on fifteen minutes later for sixty seconds on a different frequency and using different call letters."
He handed Darmstadter a typewritten list.
There were three columns. The first gave times, starting at 1500 and ending at 1745. Sometimes there was nineteen minutes between transmissions, and sometimes as little as eleven minutes. But there were no two intermissions alike. The second column listed the frequency of the transmissions. No two of these were alike. The third column listed the three-letter identification code that the transmitter would send, endlessly repeating them for the period of time it would be on the air.
"Clever," Darmstadter said.
"It presumes our guy on Vis has the transceiver, and that it's working, and that we'll be able to pick it up when we have to," Canidy said.
"And if we don't?" Darmstadter asked.
"That could pose some problems," Canidy said.
"You'll notice that the Point of No Return on the chart is here, and the point where we hope we can pick up the Vis RDF transmitter is here."
Darmstadter saw that the first place they could hope to pick up the direction finding signal was at least two hundred miles from the Point of No Return.
"And if we don't get the RDF signal?"
"Then we go down on the deck and try to find it by dead reckoning," Canidy said.
"That would be kind of hard, wouldn't it?" Darmstadter asked.
"Think positively, Darmstadter," Canidy said dryly.
"But since you posed the question, I think it would be impossible."
"And then what?" Darmstadter asked.
"Then you have a choice," Canidy said.
"You can take the airplane over the Yugoslav mainland, bail out, and take your chances that the partisans might get you before the Germans do. If the partisans get you, you're home free. If they don't, you'll have to take your chances with the Germans."
"What do you mean by that?"
"You tell them you were on a bombing raid, got lost, and bailed out when you ran out of gas. If they believe you, you sit out the war in a Stalagluft la prisoner-of-war camp for aviation personnel]. If they don't, you're in trouble."
"And where are you and Dolan going to be while I'm taking my chances with the partisans?"
"Dolan and I will have drawn the "Go Directly to Jail, Do Not Pass "Go" and Do Not Collect $200' card," Canidy said matter-of-factly.
"We can't get captured."
"Why not?" Darmstadter blurted.
"Because the Germans can find out anything they want to know from anybody, if they put their mind to it," Canidy said.
"And there are certain things that Dolan and I know that you don't, and that the Germans shouldn't."
"What are you going to do," Darmstadter asked, horrified, "to keep from getting captured?"
Canidy ignored the question. Instead, he handed Darmstadter another typewritten sheet of paper.
"There will be a bombing raid by B-25 aircraft on the boot of Italy," he said.
"Here're the details, what you would be expected to know if you had gone on the mission. Memorize as much as you can, especially your unit, your aircraft number, your departure field. Use your imagination for the names of the crew.