Guardians of Ga'Hoole 13 - The River of Wind

crossed.”
    “You mean, if we use this we can find our way through the windkin to the trough or the central stream, or whatever you call it?” Gylfie asked. The tiny Elf Owl had hopped onto Twilight’s shoulder to get a better look at the fragment of paper Bess had just set down.
    “It will help you. You see, there is an equal sign by these symbols and then a little section of wavy lines. And here, when you look at the larger fragment, you can see that some of these symbols have been dropped into the pattern of wavy lines every once in a while. I think they are a sort of key to the direction of the wind currents, but I’m not sure I quite understand the symbols.”
    “Great Glaux!” Soren and Otulissa both blurted out.
    “What is it?” Bess asked. “Do you understand the key?”
    “These are standard…well, almost standard weather, wind, and temperature symbols that we all use in weather interpretation,” Soren replied.
    “ Almost standard?” Twilight said, and took a perch above Soren and Otulissa.
    “Yes,” Otulissa answered. “Almost. These look like a very ancient form of the symbols we know. That triangle with the little tail on top—well, the tail is different,but it means rising temperature in this part of the air currents.”
    “And those sort of mountainy-looking things,” Martin said, “that means thermal upswing, which is different from a regular updraft—more gradual, not so sudden.”
    “Look at that!” Ruby gasped. “It’s a bird skull. A tumblebones!” Ruby was also a member of the weather-interpretation chaw, and this symbol had remained the same for years. The rim of a hurricane’s eye was sometimes called a tumblebones. If a bird was caught in a tumblebones, it spun around and around until it died. It was said that even its bones could never escape.
    “But this isn’t a hurricane we’re looking at here,” Twilight said.
    “Not cyclical winds.” Otulissa had become quite thoughtful as she peered down, studying the wavy lines and then glancing between them and the key. “These are basically high, fast, thermal drafts. They flow contrary to the weather vectors that we are familiar with. But you see this key really applies to the edges. The windkins, including the tumblebones, are the crisscrossing drafts that one has to climb through to get to the central trough. Imagine a ladder of wind—or even a very violent baggywrinkle—that we would climb at the edges of a gale, but much more dangerous. The windkins brace thecentral stream, more or less. Think of them as eddies that swirl off the central current of a river. They can be very confused, tumultuous, rotating in opposite directions. To cross them in order to enter the stream and to get out at the end—that is the hard part. But the key will help.” Otulissa hesitated. “I see only one problem.”
    Bess blinked and wilfed a bit. Mrs. P. sensed that Bess saw the problem, too, and Mrs. P. had a glimmer of what that problem might be.
    “Yes?” Soren said.
    “What’s the problem?” Gylfie asked.
    “How do we get back? Does the current go in reverse? And the key, does it apply to just going one way or can we somehow return using the same key? Perhaps there are differences coming back and it won’t work,” Otulissa said. “Can we reverse it?”
    They could all see Bess hesitate. “Not exactly reverse it. And I have tried to do some inverse mathematics relating to standard air currents…”
    “Yes, I can see that might be helpful, but what if we tried a quadratic differential to the fifth power?” Otulissa said.
    “I’m lost,” Soren muttered.
    “Oh, I understand completely,” Twilight snorted.
    “Perhaps,” Digger said in his slow, thoughtful way, “we need not resort to mathematics at all.”
    “And why not?” Gylfie exclaimed.
    “Well,” Digger continued, “what I am thinking is that we are just now learning about this sixth kingdom. But they apparently have known about us for a long time. How these fragments got here is anyone’s guess. But they got here, and this means some owl, some emissary from the sixth kingdom, came here at some time in history. Therefore, can we not conclude that if they came here there is a way back, a way from there to here ?”
    The owls looked at Digger, stunned by the lovely simplicity of his notion.
    Soren turned to Coryn. “All right. So we’ll go?” Coryn nodded.
    Mrs. Plithiver now coughed delicately. “There is one thing I would like to suggest,