Encouraged, Yalda searched the sky for more clues, but instead of receiving any revelatory insight she merely recalled another source of puzzlement. “The sun has no trail,” she complained.
“Exactly!” Vito replied. “It can’t be the turning of the world that makes the trails, or the sun would have one too.”
Yalda closed her rear eyes and tried to picture what was happening. Never mind the stars; if red light was so sluggish, how could the sun cross the sky without leaving a smudge of red in its wake, forever lagging behind the swifter greens and blues? “Doctor Livia said sunlight is too blue. So does it have no red or green in it at all?”
“No, it has them,” Vito insisted. “Blue is strongest in sunlight, but it has about as much of the other colors as the stars do.”
“Hmm.” Yalda imagined the sun as a blazing blue-white disk, and the world as a cool, gray circle off to one side, slowly turning. “Light flies out from the sun, with two colors, red and violet, starting the journey side by side. But as surely as Lucia will beat Lucio in a race, the violet light will strike home first—and then the world will turn a little, moving the sun across the sky before the red light arrives. So why aren’t the colors spread out?”
Vito said, “You just described a single flash of light leaving the sun. But the sun doesn’t flash, does it? It’s always shining.”
Yalda was bursting out of her skin with frustration. “Then how does it work? How does it make sense?”
Vito said, “Pick a star trail, and tell me exactly what you see.”
Yalda opened her rear eyes and complied, forcing herself to speak calmly. “I see a faint line of light. It’s violet at one end, then along its length it changes to blue, then green, then yellow, then red.”
“And are you seeing these colors at different times,” Vito pressed her, “or are you seeing them all at once?”
“All at once. Oh!” Her father’s simple question had thrown her old mental image into disarray. She’d been picturing red and violet light arriving at different times, but apart from reasoning that the sun would move across the sky in the interim, she’d ignored the timing completely, blurring the two events into something she expected to see in the same instant. “I have to think about what I see at one moment,” she said, “not about the light that leaves the sun at one moment.”
“Yes,” Vito said. “Go on.”
“But how does that change things?” Yalda wondered. “If I see red light and violet light at the same time… then the slower, red light must have left the sun earlier.”
“Right. So how does that affect what you see?”
Yalda struggled to picture it. “Where the sun is in the sky depends on which way the world is facing when the light arrives, not when it left. The red light left earlier, but that makes no difference—we just see whatever reaches us at the time we’re looking. So we see all the sun’s colors in the same place, not spread out in a trail.”
Vito’s rear eyes widened with approval. “That wasn’t too difficult, was it?”
Yalda was encouraged, but still far from confident that everything made sense. “And the stars? Why are they so different?”
“The stars are really moving,” Vito reminded her. “Not just rising and setting with the turning of the world. Between the time when the red light we’re seeing now left a star, and the time when the violet light we’re seeing now followed it, the star will have moved far enough for us to see the different colors coming from different directions. When we look at the sun, the violet light and the red light follow the same road, even though the red light begins the journey earlier. When we look at a star, the violet light’s coming to us from a different place, along a different path than the red.”
Yalda turned this over in her mind. “If the stars are really moving,” she said, “then why don’t we see them move?” The colored worms were all pinned to the rigid black sky, sharing, but never exceeding, the illusory motion that came from the world’s shifting gaze. Why didn’t they advance along their own trails, wriggling out of their constellations into fresh new patterns every night?
Vito said, “The stars are moving quickly, but they’re very far away. Even with a keen eye and a perfect memory, it would take us a lifetime to notice any change. But we’re lucky, we don’t have to wait that long. Some light trails show us in a single glance what happened over many generations.”
The red light from the fields around them lit the way now. The familiar glow made Yalda sleepy, though the strength in her limbs was holding out well enough. If Dario could cling to her as he dozed, lost to the world but still disciplined enough not to slacken his grip, maybe she could close her own eyes and sleepwalk down the road. If only Vito had brought a rope to put around her shoulders and guide her steps, it might not have been a bad idea.
When she saw the lavish jumble of colors ahead, Yalda wondered if she was fully awake. Vito’s body was partly blocking her view, and the strange apparition jittered around him, revealed and hidden in turn by the rhythm of their steps and the undulations of the road.
The road came to an end. They walked across scrubland strewn with the kind of weeds and low bushes that Yalda spent most of her days uprooting. The plants’ tiny flowers shone up at her from around her feet, but the browns and yellows that, back on the farm, marked tiresome blemishes spoiling the wheat’s pure light struck her very differently now. She stepped around them gingerly, no more willing to crush them than she would have dared trample a neighbor’s crop.
The nearest trees weren’t tall, and though it was hard to be sure in the unfamiliar setting Yalda thought she’d seen their like in uncultivated corners of the farm, or lining the streets of the village. They might have been sisters to the scrub plants; their muted colors were much the same. Behind them, though, exotic giants loomed, strewn with blossoms of every hue.
Dario stirred and opened his eyes. Yalda expected him to mutter some complaint about the lengths to which they’d gone for the sake of quackery, but instead he gazed up at the lights in thoughtful silence. Perhaps he was lost in reverie, drawn back to memories of his youthful adventures with Daria.
Yalda followed Vito into the forest. The undergrowth soon became too thick for her to avoid treading on the smaller plants, and she had no choice but to keep her soles as hard as she’d made them for the pebble-strewn road; if she’d softened her feet, as she did when she worked in the flower bed, the sharper stems would have lacerated her skin in no time.
She kept her front gaze locked to the ground, measuring every step, but after a while she grew confident enough to lift her rear eyes from her passenger toward the festooned branches above. Flowers wider than her shoulders shone up into the darkness, their violet petals draped across a network of supporting vines; she could not see their light directly, but the glow seeping through each petal’s underside was bright enough to cast shadows. Around these monsters, smaller blooms in shades of orange, green and yellow crowded every branch and twig.
When they passed through a swarm of mites, Dario shuddered and cursed; Yalda could shake off the insects herself with barely a thought, but her grandfather’s skin was not so fast to unseat them. He unwrapped two of his arms from around her torso and began to flail at the creatures, stretching the stubby fingers that had locked his hands together into broad fans better suited to sweeping the nuisance away.
As they threaded their way between the trees, the violet behemoths overhead gave way to a kind of cousin, slightly smaller, with intense green flowers sprouting from the vines that had previously been bare. Some of these faced down into the undergrowth, dazzling the travelers; others were turned toward the sky. Yalda tried to picture how the forest would appear from high above the trees, a giant’s flower bed beside the staid red wheat fields.
Vito stopped and looked around. They’d reached a small clearing where the flowers were as bright and varied as Doctor Livia could have wished, while the trees were not too closely spaced nor the undergrowth too tangled. If the forest held a better place to spend the night they could have searched until dawn before finding it.
Vito addressed his father. “What do you think?”
“This will do.” Dario turned to Yalda. “No arborines here, I promise.”
“They don’t frighten me,” she said.
When Dario had climbed down, Yalda began resorbing the top halves of her long front legs. She was too tired to think carefully about her shape, but all it really took to regain her old posture was a forceful renunciation of the wariness she’d cultivated during the trip, when relaxing back to normality would have sent her grandfather sprawling onto the road.
Vito emptied his pouches onto the ground and made himself bipedal too, then he and Yalda worked together to dig spaces for the three of them to sleep. The roots of the plants ran deep, and Yalda’s fingers had to bifurcate three or four times to slip into the soil alongside them and prise the whole mass loose; still, with her father helping the whole task was not too daunting. The worms whose homes she was wrecking were fatter and feistier than those she was used to, and after realizing that they weren’t simply going to flee from her touch she started flinging them away across the clearing.
By the time the three indentations were ready, Yalda was almost asleep on her feet. As Dario waddled toward his bed on two short legs—the only limbs he was now sporting—he turned to Yalda. “Thanks for bringing me here, Vita. You did a good job.”
Yalda didn’t correct him; whatever was going through his mind, he’d managed to make the compliment sound sincere. Vito shared a glance with her that she took to express amused concurrence with Dario’s sentiment, then he bid her goodnight.
Yalda was exhausted, but she stood for a while beside her grandfather, gazing down at his sleeping form. Giusto had claimed that he’d seen Dario glowing yellow at night. If they wanted to judge the efficacy of Doctor Livia’s cure, shouldn’t they check for this symptom, both now and when they returned? Yalda had noticed that she cast a multitude of shadows, so she’d hoped to see how Dario appeared from within them—but alas, none was deep enough to reveal what light, if any, was emerging from his skin. Wherever she stood, she couldn’t shield him from every flower at once and observe the luminosity of his body alone.
It was frustrating, but as she gave up and crawled into bed, Yalda thought of the bright side. If any light emerging from Dario’s skin was so faint that it was hidden by the forest’s glare, surely that meant that whatever hue he’d been losing back on the farm was now being replenished faster than it was leaking away.
She wriggled deeper into the cool soil, squashing a few worms who’d escaped her earlier evictions, and gazed up into the violet backlight. She thought about the arborine—skulking along the branches somewhere, angrier than the worms—but if he came for her in the night she’d been forewarned. And if he snatched the men, smaller morsels that they were, she’d forego Amata’s tortuous history of guilt and redemption and just cut them free first thing in the morning.
To Yalda’s delight, the forest by day did show some fidelity to Dario’s story: many of the smaller flowers in the undergrowth, shielded from sunlight by the canopy of branches, really did retain their radiance.
Most of the clearing, though, was not entirely sheltered from the sky. With the violet flowers curled up into crumpled sacs, sunlight spilled through the net of vines that had supported their outstretched petals, mottling the ground with brightness.
After breakfast, Yalda dug storage holes for the loaves they’d brought, and Vito used some of the groundflower petals in which they’d been wrapped as lining. Yalda didn’t trust the worms here to obey the usual rules, but her father assured her that the pungent scent of the petals would keep any vermin away.
Once that job was finished, Yalda had nothing left to do but gaze into the forest. It was a strange situation; if she’d been moping around on the farm Vito would have quickly found her a task, and if there’d been no work at all her cousins and siblings would have dragged her into some game or other with their usual boisterous energy.
At noon, Vito brought out three more loaves. Dario remained half-buried as he ate, emitting unselfconscious chirps of pleasure. Yalda stood watching the slight movements of the branches around her, trying to unravel their causes. Over the course of the morning, she had learned to tell the difference between the swaying motion brought on by the wind, which was shared by many branches at once, and the trembling of a single branch when a small lizard ran along it. Sometimes she could even spot the successive rebounds when a lizard launched itself from one branch and landed on another.
“What do lizards eat?” Yalda asked Vito.
“Insects, maybe,” he replied. “I’m not sure.”
Yalda contemplated the second part of his reply. How could he not be sure? Were there things about the world that adults didn’t know? Dario offered no verdict on the lizards’ diet, and though he might just have been too preoccupied to bother, Yalda was beginning to wonder if she’d misunderstood something important. She’d thought that every adult’s role was to instruct their children and answer their questions, until the children knew all there was to know—by which time they were adults too. But if some answers weren’t passed down from generation to generation, where did they come from?
Judging that it would be impolite to probe the extent of Dario’s knowledge in his hearing, Yalda waited until he had dozed off again.