Lanson smashed his fist down on the table top. “Good!” he exclaimed grimly. “I'd like to make things hot for somebody, and it'll at least be easy enough to catch whoever is using the wire.” MacVightie shook his head.
“Oh, no; it won't!” he said evenly. “I didn't mean to give you that impression, and don't you make the mistake of under-estimating the brains we're up against, Lanson. I'm no expert on telegraphy, that's your end of it, but I know they wouldn't sit in on any game where they didn't hold trumps up their sleeves. Get me? Now let's see what it looks like. As I understand it, these messages, no matter from what point on the division they are sent, would be heard on every sounder on the line—that's right, isn't it?”
“And it might be an operator working with them as an inside man; or, with the necessary outfit, the wire could be tapped at any point, couldn't it?”
“Yes,” said Lanson; “but the minute he starts in, we could begin to 'ground' him out.”
“Go on!” invited MacVightie. “I'm listening.”
“We could tell whether he was working east or west of any given point,” explained the superintendent; “and, with the operators instructed beforehand, practically narrow him down to, say, between two stations.”
The Hawk, as he, too, listened, permitted an amused smile to flicker across his lips.
“Um!” said MacVightie. “And would he be aware that this 'grounding' process was going on?”
“Yes—naturally,” admitted Lanson. “We can't prevent that.”
“That doesn't sound good to me,” he said slowly. “All he'd have to do would be to beat it then—and the next time start in fifty miles away, and you'd have to begin all over again. And, besides, who's receiving the messages? You can't put any tabs on that. Every sounder from Selkirk City to Rainy River registers them, and all a man's got to do is listen. You see, Lanson, it's not so easy—eh?”
“Well, what do you suggest?” he asked uncomfortably. “We can stop it.”
“But we don't want to stop it!” returned MacVightie. “We could have done that from the first. What we want is our man now. And it strikes me that the first thing to do is to find out whether one of our own operators is in on this or not. Unless the line is tapped somewhere, it's a cinch that a station key is being used, isn't it? Send some linemen that you can trust over the division. If they find anything at all, they'll find the spot where the messages are coming from, won't they? If they find nothing, we'll know we've got to look nearer home—amongst our own men.”