Tally found Matty exactly where she had known he’d be: lying on his back at the top of the Crest, looking wistfully up at the planet below them. She huffed angrily to herself as she trekked up the steep hillside. Ten minutes ‘til curfew, and there he was, buried like a corpse in the thick fields of cobalt-blue grass. Suffice to say that he owed her for hauling her butt all the way up here just to drag him back to the house before their mother found out what he’d been doing. As if she wouldn’t be able to tell by the blue stains on his clothes, anyways.

“Mum would slay you if she knew you were out here.”

Matty opened his eyes. Tally towered over him, hands stuck accusingly to her hips, those freakishly big doe eyes of hers flared into an angry glare. He grinned up at her. “It’s the only place where I can see the Other World.”

Tally rolled her eyes. “You’re not supposed to look at the Other World, Matty. And you’re definitely not supposed to break curfew.”

“C’mon, Tal. Haven’t you ever been curious about what’s down there?”

Tally hesitated, then glanced upwards. Her breath hitched in her throat. She could see why Matty liked coming up here so much. This close to the Mirror, you could see…well, everything. It was as if Earth was close enough to touch. Beyond the transparent, faintly rippling wall that separated their two worlds, she could make out the outlines of navy-blue oceans, count the green-and-brown splotches that made up continents. A faint smile curved her lips. No matter how many times Matty dragged her up here, she would never quite be able to get over the sight of Earth’s strange green land masses.

Tally shook herself and looked sternly back down at her brother. “Of course I’m curious, Matty, but rules are rules. What if you got too close to the edge of the Crest? What if you fell over and broke through the barrier? They don’t let us up here for a reason. Honestly, I don’t get you. The only spot on the entire planet where the gravity’s warped enough for you to fall up to Earth, and yet you insist on coming up here.”

Matty swatted her worries away like they were of more significance than dust mites. “The Mirror’s unbreakable, Tals, I wouldn’t be able to shatter it just by falling on it.”

Tally’s frown deepened. “Well you’d still break probably every bone in your body, and then you’d have to lie up there until border patrol brought you back down. So not only would you be paralyzed for the rest of your life, but you’d have to go to jail for at least ten years, too. Mum would have a stroke.”

Matty responded only with that infuriating smirk, the one that had driven her to insanity many a time during their shared childhood. “Come lay with me.”

Tally resisted the urge to stomp her foot. “No. Let’s go. If we run, we can still make curfew.”

“Come on, Tally.” He patted the ground next to him. “The view’s incredible. Let’s just look at it for a while.”

Tally huffed.

“Five minutes. Then we can go back.”

“No.”

“Five minutes! Give me five minutes and I’ll be your willing hostage, I promise.” He patted the turf again, invitingly.

Tally groaned, sidestepped his head, and flopped down into the grass beside him.

“There we go.” Matty grinned and rest his hands over his stomach, gazing longingly up at the swirling blue-green planet below them. “Isn’t is something?”

Tally fidgeted. “Mm-hmm.”

Matty nudged her in the side. “Will you quit twitching? Just lay still for a minute, okay? Take it all in.”

Tally exhaled, blowing her bangs out of her face, and obliged, tilting her head back and letting her eyes roam freely over the face of their sister planet. The air glittered with the pollen of the field flowers, and the grass tickled her cheeks and the exposed skin of her arms and shoulders; yet it wasn’t long before she found herself slowly relaxing into the cool, spongy ground.

After a moment, she spoke again. “Do you think they know we’re…up here?”

Matty’s voice was soft in the pervading twilight. “You know they don’t.”

Tally gazed somberly at the patchy little planet. “They can see us, though. Our—blueness, I mean. They can see our blueness, just like we can see their gray-brown-greenness. And they can see our flowers.” She gestured to the brilliant white blossoms, that lit up the dark with their sparkling silvery glow. "‘Stars,’ they call them. And we know, like, everything about them. So—why don’t they know about us?”

Matty sighed. “It’s just always been this way, Tal.”

Tally chewed her lip. “Yeah, I know. It’s just”—she inhaled—“it makes me feel kind of…small, sometimes.”

Matty reached out and grasped her hand. “Yeah. I know.” He paused. “Hey. You know what?”

“What?”

“I bet they sometimes feel small down there, too.”

“You think?”

“Definitely. In fact, I’d be willing to bet that right now, someone down there is lying in that weird green grass that they have, looking up at their sky, just like we are. And they see all of our blue glass—like, all three million acres of it"—(Tally giggled. It was true. Sometimes it felt as if their planet was nothing but miles and miles of open, rolling meadows)—“and they feel pretty small in comparison, too. But you know how you get that sort of breathless feeling when you look up at all of their oceans and clouds and big, cool continents?”

“Yeah?”

“Well, rumor has it that they get the same feeling when they look up at us, too.”

“Why? We haven’t got any oceans or clouds or big cool continents.”

“Yeah, I know. We’ve got just the opposite. Just a big expanse of dark blue space, dotted with little bits of sparkling white.”

“Exactly.”

“And that’s just what they need.” Matty turned to grin at her. “They haven’t got so much space down there anymore, so they like ours. It lets them imagine all of the spaces that they haven’t discovered yet. The bits and pieces in their own dreams that they still have to fill in. And I bet that it makes them feel better sometimes, just imagining all of the things that could be up here.”

Tally smiled, her fingers curling around his. “Oh.”

“Yeah.” He squeezed her hand and looked back up. “So no, they don’t know about us; they’ve got no idea that we’re up here. But their lives wouldn’t be the same if we weren’t. Isn’t that nice?”

Tally blinked slowly, absorbing the big, broad, beautiful face of the world that faced theirs, sparkling in all of its uncontained possibility. Her smile grew, and she nodded, content to bathe in the soft pale glow of planet Earth. “Yeah,” she whispered. “It’s nice.”