But now, as he looked up at the imposing building before him, with its chained doors and barred windows, he felt nervous about his latest mission.

Ms. Holiday, his partner and fellow spy, stood next to him. The two had worked together for nearly a year. They’d been at the center of saving the world more than once, and they had become close. Lately, she had been urging him to express his feelings. But it didn’t feel natural to talk about such things. Luckily, she seemed to be able to read his mind even when his lips were closed tight.

“It’s going to be OK, Alexander,” she said, patting him on his arm and smiling. “We’ve had tougher assignments than this one. Remember Syria? Remember when we infiltrated that street gang in Mexico? Or the time we were tied to a rocket and shot into space?”

Brand nodded. Perhaps she was right. The current mission was no more dangerous than any of the others. Mustering his courage, he hobbled up the steps, using his cane for support. Once at the top, he cupped his ear to the building’s massive door. Inside there was a tremendous racket. It sounded like a battle zone or a full-scale riot—obviously, a bigger job than two secret agents could handle.

“We’re going to need backup. Call SWAT, the FBI, CIA, Special Forces, the Green Berets—whoever can get here the fastest. Tell them to bring tear gas and riot gear. We’re probably going to need some air support, too.”

Ms. Holiday joined him at the top of the steps and pushed the double doors open. “Alexander, calm down. It’s just middle school.”

The duo stepped inside and were immediately surrounded by chaos. Spit wads flew through the air, children ran in all directions, trash spilled across the floor, and slamming locker doors assaulted the ears. Near the front door was a portrait of Thomas Knowlton, one of the United States of America’s first secret agents. Knowlton was a striking man with a thick head of hair and a courageous face. Unfortunately, someone had drawn a curly mustache on him and blacked out a few of his teeth. Brand wondered what kind of juvenile delinquent would be so disrespectful to a national hero, and then he realized any one of the kids in the hall could be a suspect. They darted about like maniacal jackrabbits, while the teachers staggered down the halls, shell-shocked and disillusioned.

“Alex, I know you don’t like change, but we couldn’t keep the kids at Nathan Hale Elementary any longer. It was time to move on. It’s part of what happens with the NERDS,” Ms. Holiday said.

“But I had just gotten my office the way I like it,” Brand said. “Now we’ve got a new school, new teachers, a new Playground—”

“Everything is online and fully operational,” Ms. Holiday said. “The new Playground is even better than the one before. Don’t worry, you’re going to think of this place as home in no time.”

A soccer ball whizzed through the air and, instinctively, Brand tapped his cane on the floor, releasing the dagger-sharp tip. Right before the ball smashed him in the face, he impaled it on the end of the cane. A tubby kid with an upturned nose rushed toward him. “Hey, that’s my ball!”

Brand pulled the now-flat ball off his cane and stuffed it into the kid’s hand. “Try to be more careful with this in the future.”

The kid looked down at his ball and frowned. Then he walked away, just as deflated.

“Oh, our new friends are here!” a voice cried from down the hall.

Brand squinted into the sea of children and spotted a little woman barreling toward them. She was short and stumpy, like a smushed Twinkie, with long hair the color of straw and the wide-eyed expression of a porcelain doll. She gave Brand a hug he did not expect and could not escape from.

“Welcome to our nest, new friends!” the woman cried.

“Our nest?” Brand asked Ms. Holiday, still trying to squirm out of the woman’s iron embrace.

The woman turned to Holiday. “You must be our new librarian. No one told me we were getting a peacock. What a beauty. I have no idea how our boys are going to concentrate with you checking out their books! Well, we’ve got a lot of reluctant readers flying around these halls, so you have your work cut out for you! We’ll have to do lunch and you can tell me all about your favorite reads! How is Wednesday?”

“Well, I just—”

“Wednesday it is!” the woman cried, clapping her hands like a happy baby. She turned back to Brand. “And you must be our plover.”

“Plover?”

“It’s a bird that cleans the teeth of alligators,” Ms. Holiday told him.

“Our Ms. Holiday is beautiful and bright!” the woman cried. “You are correct. A plover cleans up messes, swooping in to snatch the debris and take it off to who-knows-where. Just like you! I like this place to be spic-and-span, Mr. Plover.”

“It’s actually Mr. Brand.”

The woman waved a hand in the air as if his contradiction was a swarm of pesky gnats. “You’ll have to get started right away. One of the bad birdies has played a little prank and clogged all the toilets on the first floor. A couple were so backed up, they exploded, and now there’s water everywhere. Naughty, naughty birdies! You’re going to have to have lunch with me and we can talk about ideas to keep things clean. I’ll pencil you in for Thursday.”

“Um, and you are?” Brand asked.

The lady clapped her hands and giggled. “Oh, I’m a silly bird. I didn’t introduce myself. I’m Principal Dove. Get it? Dove! Like the bird!”

The spies stared at the woman for a long time until they realized she expected an answer. “Yes, we get it,” Ms. Holiday said.

If Ms. Dove’s smile could have gotten bigger it would have required surgery. She gestured to the students. “And all these children are my little birdies.”

Brand glanced around the hallway. A girl was shoving a smaller boy’s face into the drinking fountain, soaking his hair and shirt, while other kids cheered and laughed. Two boys were tossing balloons filled with shaving cream at each other. A young girl was wiping dog poo off her shoes and onto the wall.

“I think some of these birdies need to be in a cage.”

“Oh, you scamp!” Principal Dove said. “They only act like this because they are so eager to fly, and it’s our jobs to get them up into the sky and let them soar! So, can I count on you to help me teach them to fly? Peacock? Plover? Are you ready to join our flock? You know, we should all have lunch together, too—the three of us! I’ll pencil it in for Friday. No, let’s commit. It’s going down in ink.”

Just then a bell rang.

“Well, I’d better get my chicks to their coops,” Ms. Dove said. “We can’t stand around chirping all day. The two of you need to get to work. We’re so excited to have you here!”

Dove walked down the hallway, flapping her arms like an excited hen. “Let’s fly off to class, now, birdies,” she called out to the students. “Your teachers are going to lay some eggs of learning and you want to be there when they hatch!”

When the hallway was clear, the two spies stood, stunned.

“Can’t we just flunk the team and send them back to the fifth grade?” Brand asked.

“Let’s take a look at the Playground,” Ms. Holiday said. She removed a small, metallic orb covered in blinking blue lights from her handbag. It floated into the air, spinning and clicking with the sounds of internal electronics. Then it spoke in a dignified, old-fashioned accent. Its creators had programmed it with the personality of one of America’s most famous spies, Founding Father Benjamin Franklin.

“Good afternoon, team,” it chirped as it hovered in front of them. “Welcome to Thomas Knowlton Middle School, named after the father of military intelligence. I suppose the two of you are excited to get started. If you’ll step into Locker 41, I can take you to the new HQ.”

“You’ve got to be kidding me,” Agent Brand said. “We have to take the same entrance as the kids?”