Two Crows Watch from the Gallows Tree (part 14)

Gaius shuddered and stared wide-eyed at the place the letter had been. He touched his fingers together; they were still tingling as if he'd just gotten a static shock.
Sara had leaned forward as the letter disappeared, gasping when she saw it pop out of existence.
Gaius looked up at Derik slowly, trying to get his expression under control. "So what now?" he asked after a long pause.

“Now, we wait. The response will materialize near my person, but I’ll hand it over without looking at it.” Derik understood the alarm. He’d been much the same the first time. First few times, even.

"How long does it take?" How had he never heard of this before? Was this something all Southerners could do? Could it be sent to someone without a link? Was there a book on it he hadn't read yet?

“He’s got the letter already— that part’s instant. I don’t know how long it’ll take him to write up a response since I don’t know what you asked. But I imagine he’ll answer right away; he was prompt when I was talking to him not fifteen minutes ago.”

"Can you transport anything? Or just letters?"

“It depends on weight and distance,” Derik answered warily. “I can’t send anything heavier than a letter to Zander with how far away he is. But the closer the distance, the heavier I’m able to move.”

"Could you send something living? A mouse, perhaps?"

Derik blinked at him. “I mean… that takes significantly more energy… but… perhaps? In theory?” He shook his head slightly. “I’ve heard of such things happening before, but with Rangers far stronger than myself, unfortunately. I mostly stick to objects.” He bent and pulled off his boot, then sent it across the room. It thunked to the floor just under the window a moment later. “But like I said, it takes much more effort than a paper and I’m limited by my own energy. Which is low, currently.”

"Could you call something to yourself rather than send it?"

Derik considered for a moment. “I mean. If it’s within sight, sure.” He crooked his finger and the boot came floating back towards him lazily, in sight this time. “I don’t know that I’d be able to do anything out of sight. I doubt it. You’ve got to sense the vibrations to be able to manipulate them, and I’ve got to be nearby to do so. I can’t feel the vibrations of anything not in the immediate vicinity. So, like. Zander has to send the letter to me. I can’t take it from him. That sort of thing.”

Gaius's brow furrowed. "Is this something all of the South can do?"

“It’s not a Southern thing.” Derik shook his head, bending down to put his boot back on. “I live there as a cover story; I’m from a country off continent. I won’t be sharing which one. But it’s not even common there, no. It’s a special training and very well kept secret. I’d appreciate if neither of you mentioned it to anyone but Zander and myself.”

"Are there booms? Any other information on this? Which continent?" Gaius was far more interested in this now.

“No.” Derik shook his head. He didn’t like questions. He didn’t blame Gaius for them; they were reasonable. But questions were dangerous. And he didn’t want to stumble carelessly into leading him to ask questions he shouldn’t even think of having. “It’s an oral tradition, passed down from Ranger to apprentice as part of their training. It’s intentionally not recorded anywhere so people who ought not have their hands on this sort of knowledge can’t teach themselves. Individualized vetting and all that.”

"And who's to decide who should and shouldn't have this ability?"