The markings on that side of the rock rearranged themselves, clearing a large, empty, elliptical space in the middle. A long row of tiny bars lay to one side. The first ten were all green, and the rest, fifty or more, were pink. There was a square in one corner and a triangle in another one.

Nick pressed one finger in the empty space for a moment. When he pulled his hand back, there was a green dot right where he had touched the rock. A touchscreen? A drawing pad? Nick traced out “HELLO” with his fingertip and the word just sat there. Sighing, he tapped short-short-long again, and sure enough the oval cleared.

It's a start. At least it's reacting now.

Nick spent a while swiping, tapping, talking, whistling, trying to figure out what the rock did. The sky continued to brighten. It was hard to tell what the little changes in the markings meant. Some were obvious rearrangements, and some changes were very minor, like the way the row of tiny bars now had nine green and the rest pink.

Wait.

Crap.

That's a battery charge, isn't it? And it's draining. It did remind him of symbols used in electronics. Nick started breathing fast and forced himself to calm back down. All right, so I've got nine units left. Is there any way to recharge this? A gas tank? A hand crank or something?

Nick added the battery symbol to his button pressing experiments. He wasn't being very systematic about it. He was sure there were combinations he wasn't trying. I should write down notes...but the pens are busted.

Finally, Nick stumbled on an effective action: he swiped the power bar from green to pink while holding the triangle, and then five tiny images appeared, arranged in a pentagon. The first image was circled, and had a box and another battery meter symbol, so Nick tapped that. When nothing happened, he tapped it twice. Still nothing.

Tapping short-short-long on the box icon caused...something. The color specks all over the rock kept shifting, looking not quite random. Nick held his breath, waiting. After a few moments, though, the symbols froze, except for a messy pattern of dots that was blinking.

Is it stuck? I think it's stuck. Nick wondered if the damned rock was broken. Maybe it's some kind of safety feature, like “fasten your seatbelt.” Dude, if I had a seat belt, believe me, I'd... Nick stopped, then leaned over and peered at the piece of the back seat of the Explorer that was intact. It did have a seatbelt...

“Nah, that can't be it,” Nick said aloud. “It needs something. Fuel? Dude, if I had fuel, I wouldn't have to do this.” The rock continued to flash stubbornly. “Dude, seriously, there's nothing to eat. You don't...you don't eat food, do you? Human food?”

Running out of ideas, Nick picked up the apple he had stepped on, and started pressing it against every part of the alien device he could. “Come on, nom nom nom, you know you want it...” When he pressed the apple against the cheese-grater side, it stuck there. Nick was watching closely, so he spotted it when two of the little color pixels shifted slightly. Then the apple fell off.

“Seriously?” Nick tried to put the apple against the cheese-grater again but it wouldn't stick, and none of the dots moved any more. He examined the apple, and found that it had a waffle-iron look to it, with maybe a few small bits of the apple missing.

Nick looked the whole thing over again. “I don't think feeding it the groceries is going to do much, but...” He made an offering of the raw hamburger, and essentially the same thing happened. A few bits of hamburger stuck to the grater and the rest fell off. Two of the other pixels shifted a tiny bit, Nick was pretty sure.

“Okay, on the right track, but it doesn't much like the food....Hm. It's a rock. Does it want to eat other rocks?” Nick climbed out of the Explorer to grab a few of the rocks he had collected, and had to squint. A wind was blowing out of the east now, and it was actually warm. The chill rapidly left his bones.

Whoa, the sun isn't even up yet and it's this bright? No wonder Rudolph is so...bright... Nick got a sinking feeling. He turned east and the sky was bright enough that sunrise was probably imminent.

You might be reading a stolen copy. Visit Royal Road for the authentic version.

This...could be bad.

Nick didn't have any better shelter than the car, so he climbed back in. The alien rock had eaten a ragged patch of the carpet where he had set it down, but didn't seem to be interested in taking any more. Okay, it needs ingredients. Try this on for size, space rock.

This time, Nick could actually see the rock disappearing. He had no idea where it was going, though. Where does it keep its stomach? Its...garage? Storage closet? The alien device ate about a quarter of the rock before it dropped the rest. Several of the color pixels had definitely changed that time.

If I knew how to read these color dots, it might tell me what it's hungry for. What else can I offer it? Nick looked at his meager supplies, and decided to try the busted laptop. That appeared to be the right choice.

The alien device clamped on and started chewing its way through to the motherboard at once. Nick could see more color dots moving, and realized that they were starting to pair up. Maybe...one dot for how much you need, and the other dot for how much you have so far? When they match, it's all fed?

The display stopped blinking. Nick held his breath and waited. The battery symbol now had two circles around it. As he stared, he realized that there was a speck on one circle that was moving very slowly. Also, the big battery meter was down to six green bars.

He nervously eyed the very bright horizon and decided that he had better not look in that direction any more. He concentrated on the space rock. I need a name for this. Pet Rock, maybe? The speck had traveled about halfway around the circle, and there were five green bars left.

This had better do something good before it runs out of power...

The barest flicker of movement caught his eye. Nick turned the device so that the smooth side was facing him, and discovered that some kind of cylinder was being extruded, very, very slowly. His jaw dropped.

I think this thing is a 3D printer! Is it making a battery for itself? How would that work? Nick was definitely fuzzy on his science, but he was pretty sure things couldn't magically feed themselves energy.

There were now three green bars left. Nick crouched down so that no part of him was in direct sunlight, even through the window glass. He was getting worried that the radiation would be distinctly unhealthy. Maybe I should be hiding behind the hill...but then what happens if the sun rises high enough to light up the whole hill? I need a cave.

The cylinder detached from the device. There were two green bars left. Nick hefted the cylinder, wondering what it was. It seemed to be covered in some kind of rectangular grid pattern. He poked and prodded at it, feeling slightly rough edges and tiny bumps.

Then apparently he did something right by accident, as the cylinder unrolled into a long flat sheet in his hands, and became somewhat rigid as soon as it finished. I hope this is what I think it is. Nick gripped it firmly at one end, and then slowly lifted it so that the higher end got into the path of the morning sunlight that was streaming over Nick's head. He watched the battery meter on the main device, staring at the two green bars remaining. Reluctantly, he lifted a bit more of the panel into the sunlight.

The third green bar came back.

Nick let out a huge gasp of relief, and carefully propped the alien solar panel up so that half of it was in the sunlight. For the next several minutes at least, he sat and watched the meter as the fourth green bar came back, then the fifth. Nick waited, nervously staying out of the light, as the car began to seriously warm up.

In this heat, any food that needed to be kept cold was going to be ruined before long. Nick opened up the cold cuts and stuffed himself, washing it down with milk. He wanted to mess with the device some more, but disciplined himself to wait until he had at least nine green bars again. It would suck to drain it dead just as he was about to save it.

I wonder if I can make a second solar panel. It didn't eat all of the laptop... Once the device had enough power in his estimation, Nick repeated the process as best he could. It took longer for the device to eat whatever it needed from the remainder of the laptop, but it got there eventually. He carefully watched the color markers lining up again.

Probably elements? Like, the big gap on that one means it needs a lot of...silicon, maybe? Or metal? That gap between pixels didn't start closing until the device was eating the motherboard again.

Man, I wish I were a science nerd right now...Good thing this sucker is user-friendly.

The second solar panel was extruded with five green bars remaining on the device's battery. Nick tried to unroll it, but couldn't figure out how he had managed it the first time. It ended up taking him at least twice as long to duplicate whatever move he had done, and even after it happened, he still didn't know exactly what he had done right.

The good news was, propping up the second panel next to the first caused the battery marks to go green twice as fast. The bad news was, more and more of the car's interior was getting exposed to direct sunlight. Nick belatedly pulled the car door inside and cowered underneath it.

As he started sweating, Nick wondered whether he was going to die from being cooked to death.

Shut up, he told his depression out of habit. He gripped the device, and set out to discover what else it could do for him.