“Where am I?” she said, teeth chattering, to no one in particular. There didn’t seem to be a living soul for miles. Had she plugged in the wrong latitude and longitude? Had she assembled the machine incorrectly? Had her equations been incorrect?

No! That wasn’t possible. Gerdie took great pride in how thorough she was. No matter how simple the problem, she accounted for every possible solution. Her teachers often complained that she made things intentionally difficult. She had once used a whole ream of paper to prove the answer to 2 + 2! Still, here she was, in a place too cold even for Santa Claus. No, something else was wrong. Heathcliff’s number must have altered the machine’s basic function.

Shivering, Gerdie pushed the plunger on her machine, but nothing happened. The battery was dead. Her device had a self-charging fuel source, but it would be ten minutes before it was ready to teleport her again. Unfortunately, she was wearing a pair of linen pants and a short-sleeve shirt. She wouldn’t survive that long. Her fingers and toes were already numb.

“Help!” she cried. “Is anyone out there?”

Suddenly, she heard something odd. It sounded like footsteps, but how could she hear someone approaching with the roaring wind all around her? “Hello?”

There was no response, just more heavy footfalls, so Gerdie decided to move toward the sound. The weight of the teleportation device wasn’t making it easy to trek through the deep snow, but she struggled forward. She climbed up an icy slope, where she thought she could actually hear the heavy breath of her rescuer. But when she reached the crest, she saw something that just couldn’t be possible. It was nearly twelve feet high and covered in thick, curly hair. It smelled of mud, and it had long curving tusks that sliced through the air, pointing right at her. She had seen paintings of such creatures in books, and even a skeleton up close at the Smithsonian Institution in Washington, D.C., but they weren’t supposed to exist anymore. Even if she had teleported to the North Pole or Antarctica, or wherever she was, the last woolly mammoths died ten thousand years ago.

The beast seemed as startled by her as she was by it, and it reared back on its hind legs. When it came crashing back down, it roared and stomped its huge feet. Gerdie was sure it would charge and crush her flat. She stepped back, missed her footing, then felt herself plunging downward as her machine dragged her to the bottom of the icy slope. She tried to get to her feet, but the weight of the teleportation machine would not let her stand. She struggled out of its straps, then did her best to pull it behind her. She couldn’t abandon it. It was her only way back home.

But the mammoth was charging toward her, its huge head down and its tusks aimed at her heart. She rolled into a ball, and the giant creature ran right over her, missing her entirely. Somehow it managed to miss the machine, too.

She scrambled to her feet, but a blast of cold air hit her hard. She lost her grasp on the machine and fell, rolling like a snowball, end over end, until she stopped at the mouth of a cave. Standing over her were three figures wrapped completely in animal hides. They held spears and grunted angrily at her.

The trio leaped forward with spears in hand, but instead of killing her they ran right past and attacked the mammoth. Their weapons were crude—nothing more than sticks with sharp stone points—but they were thrown with deadly accuracy. One went into the creature’s front leg and the second into its head. The third caught the beast in the heart. It wailed in agony, finally falling forward onto the snow. The creature was dead.

As she watched, stunned, Gerdie was lifted to her feet by strong hands. More of the strange warriors had stepped out of the cave and were helping her. They pulled her inside the cave, deep into its darkness.

By the light of flickering torches mounted on the walls, she caught glimpses of cave paintings: hunters fighting herds of mammoths, strange deerlike creatures, something she thought might have been a saber-toothed tiger. The paintings looked fresh, as if recently painted.

With each step she felt the bitterly cold air growing warmer and warmer. Wherever these people were taking her there was a fire. Finally, she was led into a huge room. At its center was a bonfire with nearly forty people gathered around it—children, babies, parents, elderly men and women. All were wearing animal hides, like her saviors, and a few held long, pointy spears.

Several of the women sprang into action. They escorted Gerdie close to the fire and gave her a crude cup full of an earthy tea. They urged her to drink. The liquid rolled down her throat like lava, warming her to her toes.

“Where am I?” she asked.

The crowd looked at her oddly. It was obvious they did not understand her. Who were they?

And then a theory began to unfold in her mind. Clearly, she had not been teleported as she had intended. Could her ugly little machine actually allow her to travel through time?

And then her heart was racing. “My machine,” she said, trying to mime the size and shape of it. “It’s out there. I need it!”

The people watched her panic with confused faces. They had no idea what she was saying. They would be no help. She would have to go back out into the snow and get her machine. She couldn’t be trapped in the past forever.

Just as she was ready to bolt for the exit, the three warriors who had killed the mammoth came in and joined the crowd. One of them held her machine. Overjoyed, she raced to them. “Oh, thank you! Thank you! You have no idea how important this is to me. It’s my only way home and …”

The warrior removed her hood and gave Gerdie a shock even more powerful than coming face-to-face with an extinct monster. This “Eskimo” was small with kinky red hair and bad teeth. She had big feet and long arms and legs and a face like a Bigfoot. She looked exactly like Gerdie.

The other two warriors lowered their hoods and Gerdie got another shock. They looked exactly like her sisters, Linda and Luanne. She scanned the cave and quickly picked out a perfect match for her mother. Old Mr. Carlisle from next door was feeding the fire. A carbon copy of her seventh-grade teacher, Ms. Romis, was hovering nearby. Almost everyone she knew had a twin in that cave.

Dumbfounded, she sat down on the ground and gazed at her invention. It wasn’t a teleportation device, and it certainly wasn’t a time machine. One look at these people with their familiar faces and she immediately knew what this ugly, backbreaking, wonderful device really did. It had taken her to an alternate reality. She was on another Earth.

She sat pondering what it all meant. Would the government want such a machine? Was there a practical use for it that would win her the money she so desperately needed for her plans?

As she contemplated this, she felt something jabbing her in the foot. She reached down and found a smooth stone beneath her heel. She almost tossed it aside without a glance, but then the firelight glinted off it. She examined it more closely. It was as big as a marble, but each of its crystal facets was clear and flawless.

“This is a diamond,” she said to herself, then looked at the hovering crowd of cavepeople. “I found a diamond on the ground. Do you have any idea how much this might be worth?”

The girl that looked just like Gerdie gestured to a corner of the cave. There, lying in a pile, was a heap of diamonds, unwanted, like discarded trash.

Gerdie hopped to her feet, preparing to stuff her pockets to the limit with jewels, when her machine came to life. With its batteries fully charged, the little ball of light appeared and grew. Before she could get her hands on another jewel, there was a flash and she was gone.

A moment later, she found herself back in her room. Out the window she saw angry people. Some were looking under the hoods of stalled cars. Others were pointing at their darkened houses. Gerdie suspected her return was responsible for the blackout, but it was a small price to pay. She had created something the greatest scientific minds could only theorize about. She looked down at the sole shiny diamond she had managed to bring back home, and suddenly, Gerdie Baker wasn’t so sure she wanted to sell her ugly old invention any longer.