The after-school coding camp met in one of the third-grade classrooms that wasn’t Lucy’s. Once the lady-in-charge-of-everything, Colleen, checked her off on the attendance clipboard, Lucy surveyed the space where fifteen or so kids had gathered, hoping to find someone to sit with. Most of the kids were from the other two third-grade classes, but Lucy knew a few of them.

Boogie Bass was always falling out of his chair at lunch in the cafeteria, and then laughing about it afterward. Lucy might as well sit next to him, not that she had ever fallen out of her chair. But if she did, she had a feeling Boogie would grin and make her feel it hadn’t been such a catastrophe.

Sure enough, Boogie gave her a big grin as she slipped into her seat.

“You weren’t in cooking camp or comic-book camp,” he said. “They were awesome, but this one is going to be the awesomest!”

Lucy tried to return his grin. What if coding turned out to be as mega-frustrating for her as Elena had warned it would be?

When all the campers had filed in, Colleen introduced the camp teachers, Preston and Pippa. They looked different from what Lucy had expected. Because they knew everything there was to know about computer coding, Lucy had thought they would look more computer-y—maybe like C-3PO and R2-D2 in Star Wars. But they didn’t look like robots at all. Preston was short and chubby, like someone who would run a cooking camp. Pippa was tall and slim, with a mane of long flowing curls, like someone who would run an acting camp, maybe even a movie-star camp.

“Okay,” Pippa said. “You’re here for coding camp. So what is coding?”

It’s a way of making kangaroos dance. But Lucy wasn’t going to raise her hand to say that.

Nolan Nanda, who was sitting on the other side of Boogie, was the first with his hand in the air.

“Coding is how people give instructions to a computer so the computer will do what they want it to do,” Nolan said in a slow, careful way, more like how Lucy had thought a coding-camp teacher would talk.

“Exactly,” Pippa said.

Boogie beamed at Lucy. “Nolan knows everything,” he told her proudly.

“Next question,” Preston went on. “Are computers smart or dumb?”

“Smart!” most of the campers shouted. Lucy didn’t shout anything, but she didn’t think computers were very smart if they had to have a person sitting at the keyboard telling them exactly what to do.

Preston and Pippa both shook their heads.

“Nope,” Pippa said. As if she didn’t want any computers to hear her and feel insulted, she whispered, “Computers are dumb.” She went on, “Sure, computers can do amazing things. But they can do those things only because some human being told them what to do. In this camp, you are going to be that human being.”

So Lucy had been right! And now she would be the human being—just like Elena!

Preston took over. “When you give instructions to a human being, the human being can often figure out what you meant, even if it isn’t exactly what you said. Okay, now I need a human being.” He looked around the room and pointed to the girl sitting in front of Nolan. “You. What’s your name?”

“Nixie.”

“A fine name for a human being! All right, Nixie, please walk around the room.”

Nixie giggled as she hopped up from her seat, strutted around the desks and chairs, and then plopped back down into her seat again.

“Ta-da!” Nixie said. “Was I a good human being?”

“You were an excellent human being,” Preston said.

Now it was Nixie’s turn to beam.

“The rest of you: What are some of the things Nixie did that a computer wouldn’t have known to do because I didn’t include those things in my instructions?”

No one raised a hand, not even Nolan. Lucy tried to guess the answer. Well, Nixie had giggled, and a computer wouldn’t giggle. And Nixie had walked quickly, and Preston hadn’t told her how fast or slow to go.

After a long pause, Preston answered his own question: “She stood up first.”

That was true! Nixie had also sat down at the end, without being told to do that, either.

Preston seated himself in the teacher’s chair and started to “walk” his feet away from the desk, scooting the chair along with him. All the campers laughed, including Lucy.

Then he went on: “Nixie walked around the perimeter of the room—the outer edge—instead of just randomly through the desks. But walk around the room could just mean walk all over the place, right?”

Now Preston started to “walk” his chair right into the desk of one of the kids sitting in the first row.

“Oops!” Preston said, bumping the kid’s desk, as the campers laughed again. Lucy hadn’t expected the computer teachers to be so funny.

“Nixie walked around the room once. Did I say to walk around the room just one time? That’s exactly what I intended for her to do, but it’s not what I told her to do. But Nixie figured out what I meant because she’s a human being, and human beings are smart. Finally, a computer wouldn’t even know what a room is—or what walking is—if we didn’t tell it first.”

“When do we get to start telling stuff to computers?” a kid asked from the back of the room.

Lucy sympathized. Even though everything Preston and Pippa were saying was so interesting, Lucy’s fingers itched to start tapping computer keys.

“Soon,” Pippa said. “But first we want you to practice thinking the way computers think. So get into small groups—four desks, or maybe five. Each of you, take something you’re really good at and try to explain it, step by step, to a group of aliens who just landed here on Earth. The list of steps to do something is called an algorithm. The rest of you, pretend to be the aliens, and ask about whatever you don’t understand. Got it?”

Lucy knew Boogie and Nolan were best friends, and Nixie was already friends with a quiet girl named Vera. The four of them started pulling their desks together. Pippa had said there could be “maybe five” desks in a group. So Lucy shoved her desk close to the other four and was rewarded by another big grin from Boogie. This time Lucy gave him an equally big grin in return.

“I’ll go first,” Nixie announced. “What I’m good at is walking a dog.”

“I thought you didn’t have a dog,” Nolan said.

“I don’t. But I’d be great at walking a dog if I did have one. Okay, aliens, first of all, a dog is an extremely wonderful kind of pet. A pet is a special kind of animal that lies in bed with you and loves you better than anyone else in the world. And an animal…” Nixie started to look worried. “This is going to take forever.”

“Just tell us how to walk the dog,” Vera suggested.

“Okay. First you pick up a leash. Do I have to say what a leash is?”

“No!” the others said. It really would take forever to explain absolutely everything to an alien.

Nixie continued, “Stoop down. Then clip the leash on the dog’s collar. Then say, ‘Come on, boy!’ if it’s a boy dog, or ‘Come on, girl!’ if it’s a girl dog. Then start walking. I mean, hold on to the leash and start walking toward the door. Open the door. Then close the door. I mean, close the door after the dog gets through the door, or else you’d squish the dog, which would be terrible. Then keep on walking. Do I have to tell about how to pick up the dog poop if the dog makes a poop?”

“No!” everyone said again.

“So that’s how you walk a dog,” Nixie concluded. “Did I miss anything?”

“You didn’t tell us what walking is,” Nolan pointed out.

Lucy remembered Preston had said computers would need to have even something this basic explained to them.

“What walking is? You guys are really dumb aliens if you don’t even know what walking is. Walking is when you take one step, then another.”

“How do you take a step?” Nolan asked. He made it sound as if he truly wanted to know.

“You—you—just take a step! Like this!” Nixie got up and demonstrated. “See?”

“We—have—no—eyes,” Nolan said in what was clearly a pretend-alien voice. “We—cannot—see.”

Nixie’s shoulders sagged. “This is too hard!” she wailed.

Lucy felt sorry for her. “Maybe say, move one foot forward one foot. Wait, that sounds totally confusing. So, move your right foot forward twelve inches. Then move your left foot forward twelve inches farther than you moved the right foot. Then move the right foot forward twelve more inches. Then move the left foot.”

She felt proud of her explanation of walking, but at the rate she was going, it really would take forever just to explain to an alien how to keep on walking. How did anyone walk a dog? It seemed impossible, and yet people did it all the time.

“You can use a loop,” Nolan suggested. “That’s a coding term for repeating the same sequence of instructions over and over again until you tell it to stop.”

Boogie was right: Nolan did know everything. He knew stuff about coding before the coding camp even began. And yes—a loop would solve the problem completely!

Nixie’s face brightened. “Okay! Then you do a loop thingy where you keep taking steps forward forever and ever until the dog makes a poop, and then you pick up the poop, and go home again. The end!”

Nolan opened his mouth as if to ask Nixie a few more questions, then shut it.

“Vera, you go next,” Nixie said.

Vera furrowed her brow. “I don’t think I’m really good at anything.”

Nixie stared at her. “You’re really good at tons of things! Tell an alien how to draw a comic.”

Vera shook her head. “That would take forever. And Nolan said aliens can’t see. How can you draw something if you can’t see what you’re drawing?”

“Some aliens can see,” Nolan said.

Nixie glared his way. “Now you tell me!” But Lucy could tell she was joking.

“Or tell them how to play the piano,” Nixie suggested.

“That would take forever, too. Well, maybe I can tell them how to play Chopsticks.”

Vera did a good job with her explanation, in Lucy’s opinion. She had never played the piano herself, but she thought she could play Chopsticks now, if she could remember how to find the two white keys right next to each other that started off the piece.

Nolan told the aliens how to shoot a basketball. Apparently his aliens could see, too.

Boogie said, “What I’m best at is being funny, but I don’t think I could tell aliens how to be funny. Wait—I could tell them how to lick a quarter and make it stick onto their foreheads. If they have foreheads. And if they have quarters.”

Even though everything about the coding camp had been great so far, Lucy felt nervous about her turn. What was she really good at? Jigsaw puzzles, maybe, but Elena had acted as if that was a dumb, easy thing to be good at. She loved reading, but the kids in their group knew how to read, so that wouldn’t be an interesting thing to explain, even if she could figure out how to explain it. Bracelet making? Elena’s rejection of her “copied” bracelet still stung. The only thing left was hair-styling, and she certainly wasn’t great at that, either. But she had to say something.

“Okay, aliens,” Lucy said, once Boogie’s aliens had well-licked coins stuck onto their foreheads. She could hear her voice coming out small and wobbly. “I hope you have hair. Because I’m going to tell you how to make a double bun.”