Caught in a massive prehistoric mudslide, the fossils of the Burgess Shale are almost perfectly preserved, continued the encyclopedia, and give us a clear view of the late Cambrian period.

  Myles scrolled down to see the bizarre collection of creatures unearthed in the shale. The Anomalocaris—a frightening beast with a round, tooth-filled mouth. The Hallucigenia—a tiny multilegged thing that seemed so strange to the man who discovered it that he was convinced he was hallucinating.

  But nothing could have prepared him for the sight of the Opabinia!

  It was spectacular, and like nothing Myles had ever imagined. Only three inches long, the unearthly creature had rows of gills running down the sides of its body, a single clawed arm growing from its head, and five eyes that gave it sight in every direction at once. It was weird, and wonderful.

  No creature found in the Burgess Shale survives today. In fact, there is nothing even related to these creatures anywhere in the world. The end of the Cambrian period is marked by their mysterious extinction. These creatures were unique, and unlike anything else that ever lived.

  Myles reached into his pocket and pulled out the strange hooked tooth Ryne had given him. Instinctively he knew that this was the tooth from the garbage-disposal mouth of an Anomalocaris!

  The great extinction uncovered in the Burgess Shale forever changed the course of evolution, in ways impossible to comprehend.

  Myles gripped the tooth tightly in his hand, wondering what all this had to do with him.

  * * *

  The time traveler next appeared in a phone booth as Myles walked to school the next day. They took the long way, speaking of things wonderfully complex and incomprehensible. Ryne bragged about his great knowledge and dazzled Myles with talk of temporal fractals, dimensional loops, and quantum-multiplistic theory.

  “We have come to understand that there are eighteen distinct focal points in Earth’s history,” explained Ryne. “Some of them are prehistoric and others more recent—but put together, these eighteen events have determined the course of life, and of humankind.”

  “What are they?” asked Myles, hungry to know the great answers of the universe, uncovered in the Age of Understanding.

  But Ryne shook his head. “Not for you to know… But I can tell you this—the event that created the Burgess Shale five hundred million years ago is one of the most important events of all. It’s also different.”

  “What makes it so different?”

  “Because unlike any other prehistoric event,” explained Ryne, “our sub-molecular analysis of the Burgess Shale indicates that there was conspicuous human intervention.”

  Myles wrinkled his brow in confusion. “What do you mean?”

  “I mean that at the time of the great Cambrian extinction… people were there. Two people, to be exact.”

  “People? But… but how?” asked Myles. “People wouldn’t be around for millions of years….”

  Ryne produced a phone-like device from his backpack—just like the one the first unlucky time traveler had carried. “This is how.”

  Myles looked at it closely to see that the phone had a glowing green button, dead center.

  “It has taken hundreds of years to generate enough energy to power a five-hundred-million-year time transport.”

  “To the Cambrian period!” Myles shouted. “To see what really happened!”

  “You’re catching on!” said Ryne, placing the time-phone-thingy in Myles’s hands. “This is yours. I have my own.”

  “Wait—You mean—”

  “I mean that you are to accompany me to the distant past. You will be witness to one of the most important events in prehistory.”

  Myles held the device as if it were a tiny nuclear bomb. “Why me?” he asked.

  Ryne laughed as if the question was stupid and the answer obvious.

  “Because in our infinite understanding,” explained the arrogant time traveler, “we have concluded that of all the humans who have ever lived, you are the one who must go.”

  Myles let his words echo deep within his soul. He had always felt he was meant for something special in the grand scheme of things. Perhaps his destiny truly was a great one! But still, there was a part of him that wanted to know more—needed to know more. And he was afraid.

  “Wh-what if I don’t want to go?”

  Ryne smiled in that superior way of his. “Oh, you’ll go,” he said. “History shows that you did go, and if there’s one thing we know, it’s that history doesn’t change.”

  “But—”

  Ryne dismissed Myles’s questioning with a wave of his hand. It made Myles furious. Just because he was from the Age of Understanding didn’t give Ryne the right to treat Myles this way.

  “Whether it’s today, or whether it’s tomorrow, you’re going to hit that button,” Ryne proclaimed. “And when you do, I’ll be waiting for you there, at the edge of the prehistoric sea.”

  * * *

  Ryne did not come again. Not that night, nor the next day, nor the day after that. Myles wanted Ryne to return and plead with him to press the button. How could Ryne be so arrogant—so sure that Myles would go? But Myles knew the answer.

  Because I’ve already gone.

  Somehow, they knew the past. They understood the past, and if it already happened, Ryne was right—Myles would press that button someday and be transported to that impossibly distant point in history, when the Opabinia, the Anomalocaris, and many other strange creatures swam the seas.

  What made it worse was that Myles really did want to go. It was a grand destiny indeed to be chosen to witness one of the most important events since the beginning of time—but what good was such a destiny if he had no choice in it? Being chosen can only be special when you have the choice to refuse. Without that choice, he was merely a tiny gear in the machinery of the universe. Machinery he could never change.

  So he refused to push the button.

  He refused for a whole month. He barely ate, he barely spoke. His parents, more worried than ever, sent him on extra visits to the psychologist.

  Then came the dream. It came on a night when the wind howled and sounded alive with mournful wails. In his dream Myles was trapped in the Burgess Shale, buried beneath tons of mud that had hardened into rock over millions of years. And in the stone around him, a million creatures called out his name. “Myles… Myles,” they cried. “Come to us… join us,” they wailed. “You can’t change what has already been….”

  A school of one-clawed Opabinia swarmed around him, moving through the stone, their five unblinking eyes staring at him. He tried to scream, but his mouth was filled with stone. He had no flesh—only bone. He was the fossil now. But he could still hear—and what he heard now was his own grandfather’s voice resonating through the stone, telling the old stories that so few remembered.

  Myles awoke in a cold sweat, gasping for breath, still feeling the heavy pressure of the shale all around him.

  Finally the dream faded away, but the images remained in his mind. And that was when he knew he had to go.

  He had to see the Opabinia—because he understood what it meant to be lost when the world changed. As he lay there in bed, Myles could hear his grandfather snoring weakly in the next room. Someday, Grandfather would leave this world, and he would take with him a history that rightfully should have been Myles’s. That would be a cruel, unjust end as final as the Opabinia’s.

  So he finally took the time-phone and punched the button. Not because Ryne said he would, but because the Opabinia deserved the dignity of a witness. Someone to affirm its life and tell its tale. Someone to make it matter.

  * * *

  The moment he pressed the button, an intense pain shot through him. It was like being turned inside out, while being fired from a cannon, while boiling in acid. He saw time peel away before him, the days spinning like a strobe light until the sun and moon were streaks in the sky. But he wasn’t only moving through time, he was moving through space as well, rocketing through solid mountains, moving north, toward the Burgess Shale.

  It seemed to last an eternity, and yet it was over before Myles drew a single breath—and when he did, the air was hot and thick with sulfur, like the smell of a million rotten eggs. The sky was red instead of blue and the air so humid he felt he could almost swim in it.

  “There you are,” he heard a familiar voice next to him say.

  “Waiting long?” Myles sneered.

  “Seven minutes,” said Ryne. “Your machine was programmed to bring you here five minutes after I arrived—but, as I said, time travel is imperfect.”

  Myles looked out over the vista in front of him, and if there had been any anger, any frustration in him, it was washed away by the magnificent sight of Cambrian Earth.

  Before him was a great inland sea, surrounded by cliffs hundreds of feet high. It was near sunset, and in the fading light, creatures left phosphorescent trails like underwater fireworks, stretching as far as the eye could see.

  Myles could only stare in amazement.

  “I know,” said Ryne. “No one has ever seen such splendor, nor will anyone ever see it again.”

  “Can I get closer?”

  Ryne nodded. “You can, and you must,” was all he said.

  Myles approached the water’s edge, and there, wallowing in a tide pool, he saw them for the first time. Opabinia. They were only a few inches long, but breathtaking all the same.

  Myles scooped one up, and it wriggled in his hand. Its exoskeleton was not a dull gray armor as the renderings had portrayed it, but a smooth multicolored shell, reflecting every color of the rainbow. Its five eyes were not empty and cold, but innocent and warm. The claw that grew from its head was not spiny and rough, but soft and velvety.

  The creature was not a monster, but a wonder.

  “Take a good look,” said Ryne. “Your scientists don’t know it, but this is the last place in Cambrian Earth that these creatures still exist.” Then he pointed to the enormous cliff that overhung the great inland sea. “In half an hour, that mountainside will come crashing down, clogging this sea with poisonous mud. Everything in it will die.”

  Myles gaped at Ryne as he finally realized why this moment in time was so important. The mudslide that created the Burgess Shale didn’t just capture a sample of these strange creatures—it snuffed out their very existence! In half an hour, the Opabinia, and countless other creatures, would become extinct!

  Myles petted the back of the tiny Opabinia. How unfair, he thought, that something so wondrous had to die off.

  He was still thinking of the doomed Opabinia when Ryne grabbed his hand. By the time Myles heard the clink of metal, it was too late. He looked down to see his arm handcuffed to a chain and the chain locked to a steel spike that was embedded in the stone beneath them.

  “Wh-what’s this?” Myles asked lamely.

  “History in the making,” answered Ryne, just as calmly as could be. “Do you remember that tooth I gave you? That tooth belonged to quite a large Anomalocaris. While your scientists were only able to take the fossil and reconstruct what the creature looked like, we, in the Age of Understanding, were able to uncover its entire genetic structure… and do you know what we found?”

  Myles tugged at his chain. It clanked in the thick sulfuric air but held him tight.

  “We found two very distinct chains of DNA,” continued Ryne. “One belonged to the Anomalocaris itself, and the other belonged to the last thing the Anomalocaris ate.”

  Even in the hot air of the Cambrian dusk, Myles felt a chill rocket up his highly evolved spine. “Me?”

  “You,” answered Ryne. “No one else in the universe has your exact DNA. It took us many years to track you down, and many months trying to contact you, but ultimately we knew we would.”

  Myles screamed in furious terror, “You brought me here to be eaten?”

  “Be proud,” said Ryne calmly. “Very few people know their purpose in the universe.”

  There was a sound in the sea behind him, like a groan coming up from deep in the shimmering water. The clanking of his chain had drawn the attention of something beneath the waters.

  “No!” screamed Myles. “I won’t let it happen!”

  “No sense fighting it,” said Ryne. “It already did happen. It’s just a matter of letting the event play through to its natural conclusion.”

  Still, Myles tugged on his chains. To die was bad enough; to be eaten was even worse. But to be eaten by something that would itself die in half an hour—Myles could not imagine a more meaningless end.

  “So the only reason you came here was to feed me to this… to this thing?”

  “No,” said Ryne. “I also came to detonate this.” He reached into his backpack and pulled out a bulky device with wires and a clock. Even in the Age of Understanding, a bomb looked like a bomb.

  All at once Myles realized the full extent of Ryne’s mission. “You’re going to start the mudslide that kills off all these creatures, aren’t you!”

  “That is my purpose,” answered Ryne, “to prune the tree of evolution, and make sure that these creatures die, paving the way for life as we know it.”

  With his free hand, Myles reached for his time-travel device and punched the button. But nothing happened. In fact, the dim digital readout died completely.

  “Your transporter only had enough power for a one-way trip.”

  And with that, Ryne turned and headed up toward the cliff with his bomb of extinction.

  The water began to ripple around Myles’s feet, and the school of Opabinia wallowing in the tide pool flung themselves back into the sea, in a race to escape the creature that was approaching.

  A pearly white glow rose to the surface.

  “No!” screamed Myles “No!”

  The Anomalocaris launched itself out of the water and into the tide pool. It was only two feet long, but as deadly as something ten times its size, with sharp, gleaming pincers. It came at Myles, its circular, tooth-filled mouth ready to dine upon this newfound futuristic delight. Myles kicked it away with his foot, but it slithered back toward him again in the shallow water. Then a second one surfaced and launched toward him. And then a third.

  “I will not die this way!” Myles insisted. He knew his will to live flew in the face of history, but still he fought his destiny with everything he had.

  Over and over the prehistoric beasts attacked, but they had not evolved intelligence—they couldn’t learn from their mistakes. Each time the beasts launched the exact same attack, and each time, Myles was able to kick them away with his foot… but one slip and Myles’s foot would be caught in one of their deadly mouths, and that would be his end.

  If he could break free from his chain, he could still run away. He could make it out of the ravine before Ryne detonated his bomb of extinction. Even if history said he didn’t escape, he had to try.

  When the next Anomalocaris attacked, Myles plunged his hand deep into its mouth, gagging it, and then pulled his hand out quickly. The dumb beast bit down, missing his hand, but caught the chain—

  —and the force of its bite split the chain in two!

  Myles kicked it away for the last time, scrambled out of the tide pool, and raced up the steep slope, following the footprints of Ryne… while behind him the three Anomalocaris slipped back into the sea, in search of other prey.

  Ryne had been so sure of himself. They thought they had all the answers in the Age of Understanding—but they didn’t, did they? For Myles had changed his own destiny. He had altered the course of history and would not end up in the bellies of the doomed beasts. His DNA would never end up on that tooth! Even as he climbed the mountain he could feel the change radiating forward from this moment, toward infinity—the great serpent of time writhing in agony as all of eternity adjusted itself. It was a feeling of enormous power.

  At the top of the ridge Myles came across Ryne, kneeling over his bomb. He wasn’t expecting to see Myles again, and when he did, the color drained from his face. It was wonderful to see the Man of Understanding at a loss for words.

  “But… but you can’t be here! It’s impossible.”

  “Sorry,” said Myles, “but we, in the Age of Silicon Valley, don’t believe anything’s impossible.”

  Myles ran forward and kicked the bomb away from Ryne.

  “No!” Ryne screamed. “You don’t know what you’re doing. This bomb must go off! The mudslide won’t happen without it!”

  Now Myles was the one who could afford to be smug. “Maybe it’s just me, but I don’t believe in killing off endangered species—even ones that lived five hundred million years before I was born!”

  Myles grinned and tore the wires from the bomb. It had no backup triggers because the Wise Ones hadn’t expected that anyone would tamper with it. And so when Myles pulled its wires, its timer stopped dead.

  Ryne, his eyes wide in disbelief, backed away from Myles in terror. “It will go off!” Ryne screamed. “It has to go off! You can’t change what’s already happened. You can’t ch—”

  And then the time traveler took one step too far, lost his balance, and tumbled off the prehistoric cliff.

  Myles leapt forward, trying to catch him, but it was too late. He could only watch as the Man of Understanding tumbled a thousand feet into the great inland sea. There was a thrashing of white water, and his body was gone—devoured by a school of Anomalocaris—perhaps the same ones that were meant to eat Myles.

  Feeling weak from the thinness of the oxygen and the terror of the moment, Myles fell to his knees and found himself staring at the defused bomb. But that didn’t interest him. What interested him was the small phone-like device beside it. Ryne had dropped his time-transporter, and this one had the power for a return trip!

  Myles took the defused bomb and hurled it off the cliff, so it could do no harm. Then he programmed a date and time into the device and punched the green button.

  Intense pain turned him inside out as he shot forward to the distant future, and home.