PROLOGUE

The moment Ada ran into the room, she noticed it: a soft ruby glow fuzzing through the dropped newspaper on the sofa, like the red smears left at the end of sunset.
     "Ugh," her father said. "I put my glasses down two seconds ago . . . I was just holding them . . ." He twisted around, his mouth pursed in confusion, and Ada laughed. He was looking right at them!
     "There, Daddy!"
     "Where?" The glow was dimmer now, starting to fade out, but it was still obvious. She could hardly believe he didn't see it.
     "Right there!" She flicked the newspaper aside. Silver frames gleamed against the flowered cushions.
     He looked at her, startled. "How did you know? You weren't in the room when I put them down, were you?"
     How could he ask such a silly question? She shook her head hard, baffled at having to explain, and her black pigtails swung out like wings. "I saw them!"
     "You saw them. Through the newspaper?" He shoved his glasses on at a haphazard angle and stared at her through the winking lenses. "Are you sure?"
     "I saw the glow where things are warm," Ada told him. Her voice squeaked with impatience. "The red glow!"
     He looked from her to the newspaper and back again, his brows pinched together. Then he lifted the paper and let it hang down like a curtain with his other hand hidden behind it. "Ada, sweetheart. This might be serious. How many fingers am I holding up?"
     It seemed like a stupid game; she'd known how to count for years. He must realize that. The cloudy shape shone clearly through the paper. But she'd play if he wanted her to.
     "Three."
     "And now?"
     "One finger."
     "And now?"
     "No fingers! You're making a fist."
     He'd started nodding vigorously to himself. "Infrared vision. It has to be. And there might be more. Oh, God. We've been so focused on studying the obvious ones that we never even thought to check--​But of course, of course there might be variations that aren't visible!" The words didn't make any sense to her, and she was getting bored. She wandered to the window and he followed, then knelt beside her and put his arm around her shoulder. They both looked out on a sky of flat, featureless blue above the shingled houses lining the street. "Ada? Can you describe the sky for me? Try to tell me exactly what you see."
     Another crazy question. Why should she describe it when he could see it too? If Ada hadn't loved him so much, she might have turned sullen and refused to keep playing. "It's like peacocks."
     "Peacocks?"
     "Like a million peacocks with big curls spinning around. And there are blue waves that try to be purple, but they can't. And there's the net over everything, with gold points that go on and off. And--"
     His hand clenched so sharply on her shoulder that she broke off with a gasp. His eyes were wide and he was biting his lip. "Oh, Ada. Oh, no. My baby. Listen. Listen to me. You can't say that. You have to say, 'The sky is blue.'"
     "Why?"
     "Because it looks blue to other people. And you can never, ever talk about seeing a glow where something is warm, either. In fact--​oh, how are you supposed to know what we can see?--​maybe it's best if you never talk about how things look to you at all. Not even to your mother. Do you understand me?"
     "But why not?" His urgency was getting to her, making her blood throb in her head. Her eyes felt hot and slippery.
     "Because . . ." He hesitated. This was something he badly wanted not to say, she could tell. "Because, Ada, people might think you're a kime."
     A kime. A monster, a horror: children born with insect eyes or tentacle fingers or twitchy, hairy flippers. Kimes were rejected by their disgusted parents as soon as they were born and sent Somewhere. Ada wasn't very clear on where, but she pictured a place halfway between a prison and a zoo. Kimes were dangerous; whatever made them into monsters might be catching. She knew, vaguely, that her father went to the Somewhere occasionally to study them.
     "I'm not a kime!" How could she be, when she looked exactly like other people? She didn't have antennae! Tears were brimming in her eyes. She blinked them away, but the rainbow fringe still radiated, as it always did, from her father's golden skin, and ruby flames surged from his heart. Even through his plaid shirt they were clear to her, racing out and retreating at a quickening beat.
     "Of course not, sweetheart. You're my beautiful, perfect girl. No one could ask for a lovelier daughter. But people might make a mistake. They might think you were a kime, if they heard you say . . . the things you said to me. And that wouldn't be safe. Not safe at all. Do you understand? You can't talk like that. Not even--​especially not--​to your mother." He was squeezing her and stroking her hair to calm her down. "Tell me you understand."
     "But . . ." The thought of never being able to mention anything she saw was closing down on her like a lid. It seemed impossible. She had a sense that there were obscure rules she was expected to follow and she couldn't guess what they were. "Never say anything I see?"
     He chewed his lip. "Yes. I suppose that would be too hard." He thought a minute. "Then keep it general, keep it bland. Ada, we have to practice."
     She keened and tried to pull away from him, but he held her tight. Fury spiked through her; everything he was saying seemed so horribly unfair. "No!"
     "Please, sweetheart. Just for a minute. Please. For me. Say, 'The sky is blue.'"
     For a long moment she fumed in silence, but he wouldn't stop gazing at her with wide, worried eyes. Ada dropped her head and muttered, "The sky is blue."
     He pointed to the flowers bursting under the window, to the climbing roses shaking on the trellis. "'I like flowers. They'--​yes, yes, that's safe--​'they have a lot of pretty colors.'"
     "They have a lot of pretty colors."
     He beamed. "That's very good, that's safe. You see? You don't even have to lie. Just keep it--​okay, now say, 'Purple is my favorite color.'"
     "Purple is my favorite color."
     "Beautiful! Now, Ada, most people, they can't see a thing if something else is in front of it. The way the newspaper was in front of my hand. Do you understand? Can we practice that next?"
     Ada gave a loud, protesting whine.
     "Practice one more thing, and I'll take you to feed the ducks. And we can have cupcakes by the river."
     She loved ducks. She loved to watch the light spinning off their heads until it turned into a waterfall of more-than-green, falling straight into her eyes. There was a quick stitch of pain inside her at the thought that maybe he couldn't see ducks that way.
     "Okay."
     He got up and swept the dropped newspaper off the floor, then sat and draped it in front of his hand again. "Now. Tell me what you see. How many fingers am I holding up?"
     Four, of course. Four fat sticks of red light with a softer brilliance around their edges.
     But suddenly the truth was the wrong answer. She wavered. "I can't tell?"
     "That's right! That's right! That's safe. You can't tell!"
     "Because I can only see the paper? Because it's in front?"
     "Oh, that's my smart, smart, wonderful girl!" He jumped up, scooped her into his arms, and spun her, and his enthusiasm melted her resentment. She nestled her face against his shoulder. "Oh, you'll be safe! We'll be just fine. You can only see the paper!" It seemed to be the cleverest thing she'd ever said. "I suppose that's enough for today. To the ducks, my duck! We're off to the ducks!"
     She'd thought he was so happy, but now tears overflowed and spilled down his cheeks.
     I can't see your hand behind the paper. I can't see your heart inside your chest. It felt sad to her, too. The sky was blue, he said, and that was a tiny part of the truth. It was such a tiny part that it made her ache.
     "What can I say about ducks?"
     "About ducks?" He used the back of his hand to dash the tears away. "You can say, 'I love ducks. They have pretty feathers.'"
     "They have pretty feathers," Ada repeated dutifully. She wanted him to feel better.