“They’re going to Send me.”

I’m standing at the mouth of Tristan’s cave, talking to the glow beyond the darkness inside.

“They’re going to Send me,” I repeat, this time in a loud voice that quivers from crying.

Tristan practically gallops to the entrance. “What?” His face is frantic as he takes my hand and pulls me inside. “Why?”

“Because they saw me.”

“What!”

“Because of that Alula I told you about—the one I saw watching us as we were leaving. She recognized me, the feather-fanning tattletale! I just finished meeting with the Council.”

He stares at me, unbelieving. “You mean that . . . ?”

“Yes.” I sniffle, wiping my eyes. “They’ve called an emergency Sending. They’re going to Send me later tonight.”

“Tonight! But they just had a Sending last night! They can’t—” He stops and looks at me sadly, as if he’s just noticed my tears. His next words are quiet. “It’s my fault, Hess.”

“No,” I say and laugh a little, though it really isn’t funny at all. Tristan pulls me forward and puts his arms around me. Somehow hugging him makes me feel sorry for myself all over again, and I cry even more.

“You can’t go riding the interplane without me,” he says gently. “You have to wait until I figure out how to do it, too.”

I pull away. “Sure. I can just say, ‘Hey, you know that Boytaur you caught me with at your Sending? Well, he wants to go with me, so you can’t Send me until he’s ready.’ ”

“Why can’t you hide from them? Hide here with me!”

“They would find me,” I say hopelessly. “They know all about you now.”

“Hess, you can’t go.” His voice is pleading. “You’re not ready.”

I shake my head. How many times have I said those words to an Alula before her Sending? How strange to hear them said to me now! To be the one Sent, not the one left behind. “They think I am ready. They say . . . they say I must carry out a great duty for the parallel planes.”

“What duty?” Tristan sits down to listen, his four legs folding underneath his horselike trunk.

I sigh. It was hard for me to digest the reason for the Sendings, and it would be hard to talk about it. “The parallel planes have gotten off balance. So the Council has been Sending young Alulas to live on the human plane to restore the balance.”

Tristan frowns. “How does that restore the balance?”

“Well, the Council members say there are aliens living, concealed, among the humans.”

I pause, remembering. Seeing, again, those wrinkled old faces as they leaned in around me, their eyes little stabs of brightness in the dim room. “The balance of the planes is off: this we feel,” they said. “And there is an alien intrusion: this, too, we feel. It disturbs us. It smothers us, pressing down on our world. . . .” But all I felt pressing down on me then was the weight of their watchful eyes. And as they talked on about the evil aliens and their effect on the planes, I looked away—up at the wall behind them—focusing on a shapeless stain that clung there like a patch of rotted moss. . . .

I shake the memory away with a shiver. “Remember how I told you the planes are like the levels of the creek water?”

“Yes. Each plane’s beings have a different awareness of the Great Alula.”

“Right. Well, the awareness on the human plane is supposed to be better than ours. But the aliens don’t belong there. Their awareness is like the Mantaurs’, so they’re making the awareness on the human plane too similar to our plane.”

Tristan’s face turns grave with discovery. “But if the awareness is too similar. . . .”

“Then the planes themselves—physically—become too similar.”

“Are you saying the human plane and ours could actually, somehow, blend together?”

I hesitate, not wanting to sound bleak but not wanting to lie either. “Yes, they could blend,” I say quietly, “destroying both—and eventually all—the planes.”

“Great Alula!” he exclaims. He jumps to his hooves and starts pacing around the cave.

“Don’t swear, Tris.”

“That could actually happen? Are they sure? Unless Alulas like you go there to offset the aliens’ effect?”

“That’s what they say. But the aliens are not just on the human plane. The Council says they’re spreading to the barren plane, too.”

“What?” His tail swishes involuntarily, like it always does when he’s upset. “Nothing grows on the barren plane. How can these aliens survive there?”

“I don’t know. But the Council thinks the aliens know how to ride the interplane and are Sending messengers to the other planes, just like we Alulas are.” I wring my hands, Tristan’s alarm exacerbating my own.

He shakes his head. “This is all very far-fetched. Why can’t the Council members Send themselves and find out for sure?”

I shrug. “They run everything on the skymounts. Besides, they’re too old. They need Alulas to live out their lifetimes on the human plane.”

“Live the rest of your life away from your home, on a strange plane, just because they think it’ll help the balance?”

Self-pity washes over me like cool mist over aching wings. “They say that because I associate—and fly—with a Boytaur, which is forbidden, and because I spied on one of the Sendings, which is also forbidden, they think I’m perfect for the task. They say they need ‘young Alulas who are not crippled by fear.’ ” I quote the Council’s words with sarcasm.

Tristan stops pacing and throws up his hands. “You? You’re afraid of everything!”

“I know—that’s what I tried to tell them! But all they said was, ‘Based on your actions, we find that unbelievable.’ ”

He sighs heavily. “I’ve gotten you into a great big mess, haven’t I?”

“It’s not all your fault.” I flop down on the cave’s soft floor, feeling helpless and drained. Tristan paws the ground, his front right hoof more agitated than ever as it digs its usual circle patterns in the moss.

“You know,” I say after some time has passed, “on this plane where they Send me, I’ll forget everything I know here.”

His hoof freezes in mid-circle.

“That’s why they never come back—the Alulas they Send. When the Council Sends an Alula, she loses all memory of the life she leaves.”

Tristan looks up in shock but says nothing.

I take one of my long curls and nervously twist it around my finger. The dread settles in my stomach like a nausea. “Oh, Tris, I’m afraid of forgetting.”

He kicks the ground, then says down to it, “I’ll miss you, but you won’t miss me. No fair.” He forces a smile, but it collapses into the most dejected look I’ve ever seen on him.

That look makes me want to cry all over again. I decide I’d better leave before I do just that. “Well, I should go,” I say reluctantly. But I take my time getting to my feet.

“No—wait! Let’s at least bounce-fly one last time.”

The desperation in his voice sets off a terrible ache in me, and I blink several times to hold the feeling down. “Tris, I have to get back before the Sending. They could be looking for me.” I turn, step slowly toward the mouth of the cave.

“Hess, wait!”

I swing back around and meet his eyes. Eyes like lights that reach up from somewhere deep inside him and shine straight into my feelings, into a place way down that I scarcely know. I do not want to forget those eyes.

“I wish . . . I mean. . . .” he falters, suddenly awkward. “Don’t forget to comb that mess before the ceremony,” he finally says, gesturing at my hair.

My hands fly to my hips; my wings expand in mock indignation. But I cannot help laughing when he laughs.

“I swear, you are the most exasperating Boytaur I know!”

“Not to mention the only Boytaur,” he teases. Then, his laughter converted to a shaky hope, he comes over and takes my hands in his. “Oh, Hess, don’t be afraid. You’ll be all right.” His voice, though tender, does not soothe me; it just reminds me that I may never hear him speak again. “And we will see each other someday—I promise. If not on this plane, then another.”

“Yes: another,” I say and smile cheerfully for Tristan’s sake.

My smile fades as soon as I take off for the skymounts. I’m very worried for the planes, but the heaviness of that problem is still too new and unreal to me, too impossibly awful to be true. So thoughts of my duty to the planes, my murky future, are all overshadowed by a sense of loss I haven’t felt since my mother was Sent. I should have been more careful. I should have kept my distance from Tristan, just as I did the Alulas. What was I thinking? Now I feel angry and lonely, knowing that if we ever do meet again, I won’t even know him. Tristan is just as vital to my life as his powerful legs are to bounce-flying. Without him, who will I argue with? How will I bounce-fly? And without me, how will poor Tris fly at all?

Please, Great Alula, Goddess of the Winged Women, please, please do not let me forget about my dear friend Tristan, the glowing Boytaur. Or the wonderful feel of cool wind against my wings. Or the strange sadness of the voices from nowhere. . . .

Please.