Dihani-keh looked up from her device. “Ten exponent twenty-one electron-volts.”

  Daniel stared, unsure if he’d heard her correctly. Litian-nolos were unqualified math wizards. Students here probably learned about exponents in second grade. Perhaps the unit translation had been garbled. “Ten raised to the power of twenty-one. Electron-volts?”

  She checked her numbers once more. “Yes. Very large. Ultra-gamma, yet so extreme.”

  She wasn’t kidding about extreme. Radiation at 1021 electron-volts would be the highest energy ever recorded. Even gamma ray hot spots produced in supernovae were 1015 electron-volts, at most. They were talking about radiation a million times more powerful.

  Daniel whispered to himself. “Far beyond our galaxy… and hit by planet-destroying power…” He hesitated to finish, and perhaps there was no need. Even if accurate, there were other factors to consider beyond position and energy. Daniel focused on the main one, the only factor that might make a difference. “Were they in 4-D space at the time?”

  Dihani-keh understood his question but didn’t have the answer. She spoke briefly with Theesah-ma who brought the Operations Commander into the conversation. When they were finished, Theesah-ma explained.

  “The answer is unclear. The report shows Tau set to zero. Which suggests the Chitzas had returned to ordinary three-dimensional space. A grave danger given the radiation. But another value conflicts. Their scout ships are equipped with a dimensional scanning device, like radar. They use it to search for extra dimensions. It is how they locate advanced civilizations. The scanner reported two small bubbles of extradimensional space nearby. We don’t know why.”

  Puzzling information but a hint of good news. Four-dimensional space wasn’t natural. Bubbles didn’t randomly pop up, they were purposefully stretched into existence by someone who had the technology to do it. A blast of ultra-gamma radiation at 1021 electron-volts would vaporize every scrap of matter, but only if that matter floated in 3-D space. With a fourth dimension of space in play—however small— geometry would be turned on its head. Straight lines would lose their meaning. Radiation blasting out in “every direction” might neglect to turn the corner into a fourth dimension. The reported bubbles represented hope.

  “This story isn’t over,” Daniel declared. “Far from it.”

  Daniel peppered the Operations Commander with questions about Chitza scout ship design, structural integrity, and reaction times to a major event like this. The Litian-nolo responded to each but admitted that some details could only be answered by the Chitzas themselves. He would need to contact his counterparts and establish a technical union—an interplanetary conference call of sorts, complete with political advisors who would likely slow any response.

  Theesah-ma placed a suckered hand on Daniel’s shoulder. “There is another way. While our commander contacts the Chitzas, we may find answers here on Litia. Come.” She asked Dihani-keh to remain with the operations team, then led Daniel down the ramps and out of the building.

  They hurried along a gently curving path forming the boundary of a circular field planted with a wheat-like grass, a reminder of the two-mile track on prairieland just outside Chicago where Nala’s Fermilab teammates accelerated protons close to light speed. Somehow, the Chitzas packed the same technology into a flying wedge no bigger than a Cessna SportJet.

  “It’ll be fun to see how they do it,” Nala had said on the day she’d left. She’d always had an affinity toward the diminutive hedgehog lookalikes. She called them adorably cute, clever, and resourceful—and they were. But they were also technologists with extraordinary abilities. Nala wasn’t so taken by their cuteness to miss two important facts: One, that Chitzas were her direct colleagues. And two, that they shared the same personality trait. They’re daredevils. People who rarely say no.

  When the Chitzas had offered, she’d given them an enthusiastic yes. Daniel shouldn’t have expected any other answer. In all likelihood, the Chitzas had delivered on their promise of adventure. They’d taken Nala on a thrill ride into deep space, perhaps deeper than anyone realized.

  But they’d also discovered something unusual out there. Something unexpected and potentially deadly.

  4

  Horizon

  A brisk walk brought Daniel and Theesah-ma to an enclave of tan stone buildings set within a grove of purple trees. They looked like giant stalks of rhubarb. Daniel instinctively noted the retinal based plant life of this alien world, then returned his mental focus to the issue at hand: a deep-space disaster that directly involved his wife.

  Nala was missing. Not dead, missing. And not critically injured either, since any visual that included Nala floating among tangled wreckage would only slow him down, keep him unfocused and angry. A worried Daniel wasted his talents. A grieving Daniel lost his effectiveness and squandered potential solutions.

  For now, he tucked Nala into a safe cubbyhole somewhere in his psyche and embraced this single kernel of optimism if only as a way to cope: Nala had found a way to stay alive. Somehow, he would find her.

  A billion light-years away.

  The absurd distance aligned with the correspondingly low chance of rescue. But with new sciences and bold technologies cropping up everywhere, Daniel felt far less encumbered by limits. Maybe those limits had never existed. Careful analysis, a critical eye, and attention to detail had always gone a long way to resolving the most difficult of problems. New friends in high places took care of the rest.

  Friends didn’t get much higher than Core, the cybernetic gatekeeper for the consortium of civilizations known as Sagittarius Novus. Daniel had first spoken with Core four years ago, and they’d maintained an odd relationship ever since.

  Unfortunately, among planet-sized cyborgs, this one was decidedly non-interfering. If Daniel asked Core for help, he could guess the answer and was beginning to see Core’s point. Solutions came from gaining new insight into a problem, as Core had pointed out more than once. Moreover, insight was not merely a beneficial side effect to exploration or study, it should be the principle ambition of any inquisitive species.

  Core would never be the solution to a missing scout ship, but simpler paths were still available. If they worked together, Humans, Litian-nolos, and Chitzas had the ingenuity and technology to solve the problem. No need for an all-powerful entity to interfere.

  Daniel smiled, recognizing the same reasoning religious people gave when asked why their god never showed up for duty. Roll up your sleeves and get it done yourself. Core would have said the same thing, though not quite in those words.

  Even now, Litian-nolo Galactic Operations staff were reaching out to their Chitza counterparts. Good would come from it, but they weren’t about to stop there. Theesah-ma had her own list of indispensable friends.

  “Alosoni-eff is a professor of cosmology,” she explained as they passed through the ground-level entrance to a stone pentagon with gothic spires that reached skyward at each of its five corners. “You and he see the world in the same way, lovely Daniel.”

  Daniel’s world view had never come up in previous conversations, but it might not be the comparison she had in mind. Litian-nolos tended to speak in larger contexts than Humans. A shared world view might mean that you both liked milk in your coffee.

  “Right now, anyone that can help us find that Chitza ship is my dearest friend,” Daniel answered. “At least the professor will know about ultra-gamma radiation, right?”

  “Yes, exactly.” Theesah-ma’s voice drifted down from above. She’d stretched back up to her full height. It felt like walking next to one of those oversized puppets the Brazilians made for Carnival.

  They entered a curiously curving walkway that corkscrewed vertically up one of the building’s five towers. Unlike a moving sidewalk back on Earth, the exterior frame of the spiral structure turned, lifting its occupants up the corkscrew to higher floors.

  Theesah-ma exited at the third level. Daniel followed past a series of tall entryways with no doors. Open floor plans dominated Litian-nolo buildings, Daniel’s own office door being an exception, added when they’d learned of the tendency for Humans to work in isolation.

  Theesah-ma led him into an office with walls covered by maps, star charts, and deep space photographs. Thick oversized books with worn covers leaned against each other in a disorganized stack across a desk. The place carried the musty smell of aging paper.

  A smaller Litian-nolo rose from a chair.

  It stood the same height as Theesah-ma’s young assistant Dihani-keh, but that’s where the similarity ended. This Litian-nolo didn’t have Dihani-keh’s fresh face, far from it. Wrinkles abounded across its flat, tongue like head. Eyes drooped, and knobby joints wobbled as though the ligaments holding everything together weren’t quite up to the task.

  An elder, Daniel thought. He’d only seen a few and had never met one directly. In their young society, advanced age was the exception, not the rule, with each person’s lifespan governed by a complex gene not fully understood.

  Theesah-ma introduced her friend without flourish. “Alosoni-eff. Daniel Rice.”

  The old professor leaned to one side and spoke to what looked like a potted plant on the desk. A single yellow leaf atop the pot folded itself into a crouch, then leaped to the desk. The surprisingly mobile leaf stood about ten centimeters in height on a flexible stem that flattened into a tripod at its base. Darker veins spread from the stem to its serrated edges. It looked like a leaf plucked from a cherry tree in autumn.

  The leaf’s edges pulsed with a red glow as vibrations spread across its surface and words filled the air. “My apologies, Daniel Rice,” Alosoni-eff said in Litian-nolo, with the leafy device instantly translating to English. “I have not the time to learn your language. And at my age, not the remaining intellect either. My assistant will help.” He patted the standing leaf at its point, which flexed from his touch.

  Daniel had encountered several translation devices since leaving Earth, but none quite so organic. He smiled, then offered the standard Litian-nolo greeting. “Et-tah mishi doh. No reason to apologize, Professor. I’m afraid these few words are the sum of my Litian-nolo.”

  “Not true,” Theesah-ma admonished. She had taught him more of their language, though how much he could recall varied from day to day.

  Daniel hooked a hand under Theesah-ma’s arm. “She is being kind. While on Litia, I lean on Theesah-ma and on my wife who are both fine linguists compared to me. I wish my wife could be here. She is the reason we came to see you.”

  “I have heard the news,” the professor said via the leaf’s vibrations. “My condolences, dear Human. How may I help?”

  Theesah-ma answered, “Share your experience, dear professor. How and where could a Chitza ship encounter ultra-gamma radiation? Better knowledge of the source could help us understand their chances for survival.”

  “I will try,” the old Litian-nolo said. He ran a suckered hand along the serrations of the leaf, paused, then repeated the stroke in the opposite direction. There seemed intent in both the motion and location of his touch.

  “One moment,” the leaf said on its own.

  A few seconds later, the leaf stretched to a narrow point. A rectangular window popped into the air just above it, displaying a three-dimensional graph. A curving magenta line appeared above the axes.

  “This graph maps position reports received from the scout ship,” the leaf said. “We are looking at the Chitza communications filament left behind.” More than a translator, the leaf’s comments hinted of intelligence built into what might be an organic robot.

  Daniel studied the line drawn in air. It began from a green point at the bottom, meandered gently for much of its length, then made an abrupt turn toward the right, ending at a second point colored red.

  With no labels, Daniel needed confirmation. “The Operations commander suggested they were a billion light-years away. Frankly, I have a hard time believing that. Could the position reports be wrong?”

  Alosoni-eff stroked the edge of the leaf once more.

  “The position reports are correct,” the leaf responded. “But the Operations commander is wrong. Not one billion. Fifty-two billion.”

  Daniel paused. With a variety of players, including one that looked more like it had fallen from a nearby tree, they might not be on the same wavelength.

  “Light-years, as Humans measure?”

  “Light-years, yes,” replied the leaf. “If you prefer, sixteen gigaparsecs, a direct-line measure from the red endpoint to our current position on Litia.”

  The answer was clear enough, and expressed in two different Human units, yet once again the numbers seemed impossible. In fact, they were trending in the wrong direction, farther away not closer.

  Notwithstanding the variety of star charts decorating the professor’s walls, their conversation had veered toward lunacy. “You’re suggesting that the Chitza ship ended up not just beyond our galaxy but beyond every galaxy. Fifty-two billion light-years is beyond the cosmic horizon.”

  “Yes, the Chitza position reports come from beyond the horizon of the observable universe,” the leaf agreed.

  “Astonishing!” Alosoni-eff stroked the leaf once more. “But if my assistant computes such a distance, then it is so.”

  Daniel couldn’t claim to be an expert in cosmology, but he had googled crazy ideas like “the edge of the universe” once or twice. Surprisingly, our universe does have an edge, though horizon is the better word. Sixteenth-century sailors talked of sailing off the edge of the world, but their captains knew the ocean continued beyond the horizon, they just didn’t know how far. In the twenty-first century, the same could be said for the universe. Not a single cosmologist could say with any certainty how far space might extend, but every one of them could accurately point to the horizon. The cosmic horizon.

  Like the ocean, the cosmic horizon represented not a cliff but a limit of visibility. Telescopes couldn’t see stars or galaxies beyond it because there hadn’t been enough time in the 13.8-billion-year history of the universe for their light to reach us. In fact, light from such remote places would never reach us—the rapid expansion of space guaranteed it. Twentieth century astronomer, Edwin Hubble, discovered that space itself stretched. The further away, the faster it stretched. Go far enough, and spatial expansion would outrace light itself. There would be no point in searching further.

  “Okay,” Daniel said, holding up a hand. “Chitzas are proud and for good reason. But how does anyone find a place that we can’t even see… and in fact will never see?”

  Alosoni-eff seemed to agree with the absurdity of the numbers being recited. “It is one of many dilemmas introduced by spatial compression. Until now, no one has needed to grapple with locations beyond the cosmic horizon.” The giant Litian-nolo settled into his chair and placed both bony arms on his desk. “The Chitzas may have accomplished more than we knew.”

  “There are rumors,” Theesah-ma said.

  Alosoni-eff nodded slowly. “Rumors of additional dimensions.”

  Daniel put a hand to his mouth as the light came on. “Of course… a fifth dimension of space… hell, even a sixth.”

  String theory reared its incomprehensible head once more. According to the physicists who had provided the evidence, our universe was built on a foundation of three ordinary dimensions of space, and seven more curled up at quantum sizes.

  “Compression superimposed upon compression,” Theesah-ma said. “An exponential effect carried into higher dimensions. Litian-nolos have no such technology, but perhaps the Chitzas have accomplished it?”

  Alosoni-eff added, “Expanding a four-dimensional bubble into five-dimensional space could indeed compress a gigaparsec of ordinary space, though I cannot say how theory becomes reality.”

  Daniel shook his head in wonder and newfound respect. Bloody geniuses, those Chitzas.

  Conceptually the technology wouldn’t be hard to grasp. A bicycle could do it. A car too. Simply shift into a higher gear and the same engine could double its efficiency. But had the Chitzas accomplished such a feat? They may not have been entirely honest when they’d offered a ride to Nala.

  Or had they?

  Damn it! How could I be so stupid? They told her!

  The pieces quickly fell into place. The Chitzas had accomplished something no one else had. They’d hinted to Nala, knowing that her scientific voice would provide credibility to their claim. Worse, they’d offered her a seat on an expedition to test their latest advances, dangling a shiny bauble to tempt her.

  We’re going beyond the cosmic horizon, they probably bragged.

  Nala would have jumped at the opportunity. A front row seat to an unreachable viewpoint, plus a chance to see for herself how they had pulled it off. Upon return, it wouldn’t hurt to have a Human as their spokesperson—someone who would, no doubt, tell everyone else how clever her Chitza friends had been.

  She’d left without mentioning any of this. They might have sworn her to secrecy, or she may have rationalized her silence as a way to prevent him from worrying. Daniel closed his eyes and clenched his fists in frustration.

  5

  Zero-g

  Nala arches her back, vaulting upside down, twisting, scrambling, arms flailing, scratching for something to hold onto. There is nothing but blinding white light and the shouts from her companions.

  Aussik? He’d pushed her. Onner? It sounds like her.

  There is air to breathe, she is thankful for that, but the chaotic tumbling in zero-g becomes more than her stomach can handle. She slams into something hard, sending a shot of pain through her shoulder but putting an abrupt end to the tumbling. Her stomach settles, though she still can’t open her eyes to the shocking brightness that surrounds her. Eyelids aren’t enough to fend off the invasive brilliance. Even hands cannot completely block it.

  She kicks the air and strikes something small which flies away. Clanks of metal upon metal don’t echo, they are muffled by a deadness all around. The shrieks drift farther away by the second. “Onner!” she calls out, thinking the Chitza may have called to her. She listens but hears no response.