SECRETS.

Emmet knew that everyone had them. Some kept them. Others didn’t. There were some kinds of people who, the minute you told them your secret, they blabbed it to everyone. In some cases, it wasn’t malicious. Emmet’s mother had always told him there are some people who just can’t help being blabbermouths. He laughed at the memory. That was the exact word his mother used. Blabbermouths. He missed his mom. She had a way of cutting through everything and getting right to the crux of the matter. Like when people were blabbermouths.

Sometimes people shared your secret on purpose. Maybe to get you into trouble. Or to watch you squirm, when you knew people were talking about you behind your back.

There were those, however, who would never reveal a secret. You could trust them with the deepest, darkest thing you could possibly imagine. They would never say a word to anyone. It just wasn’t in them.

Emmet found that Calvin Geaux was like that. Calvin kept your secrets. (As long as the secret didn’t involve something illegal, dangerous to yourself or others, or that might cause unnecessary dirt to get on his boat or something.)

But just as he would keep your secrets, he also kept his own.

You could plead with him, cajole him, threaten him, and it didn’t matter. Emmet was pretty sure Calvin could survive having a truckload of bricks dumped on him, and he still wouldn’t give up a secret. You could force Calvin to go to the latest concert of the most current, hottest boy band, surrounded by ten thousand screaming twelve-year-old girls, make him stay through the entire thing — twice — and he still wouldn’t tell.

It was really starting to tick Emmet off.

The reason it made him so angry is that Calvin knew the biggest secret of all. Not the secret to faster-than-light travel or who invented liquid soap. He knew the one true thing Emmet wanted to know more than anything else.

The real identity of Dr. Catalyst.

A few weeks ago, Calvin disappeared into the swamp. He wasn’t gone very long — less than twenty-four hours. But long enough for everyone to know he was missing. Dr. Geaux organized a search, but Calvin returned from his quest just in time to save Emmet, Riley, and Raeburn. The three of them were about to be overrun by Blood Jackets and Pterogators after their airboat broke down.

As they raced away from the danger, Calvin had told Emmet that he knew who Dr. Catalyst really was. His clandestine trip deep into the swamp to discover the identity of the crazed environmentalist was successful. Calvin believed he had uncovered the madman’s identity.

But that was then and this was now.

And Calvin wasn’t talking.

When the kids got back, Dr. Geaux was both relieved and furious with Calvin for running off. (And with Emmet, Riley, and Raeburn for going after him.) All Calvin would say about why he had disappeared was “I had something I had to do,” so she grounded him for six weeks. She also took away the keys to his airboat so if he ran off again he would need to travel by other means.

Emmet didn’t think that grounding Calvin did any good. It appeared as if he actually enjoyed it. He swept out the tree house and built some shelves for it. His room was even more spotless. One day he was so bored he organized their entire garage. Dr. Geaux was completely exasperated. Although even she had to admit the garage was remarkably clean. Being grounded also offered Calvin ample opportunities to sit quietly without moving for hours at a time. Something he seemed to enjoy a great deal. On the discipline-effectiveness scale it didn’t appear to have much impact. Calvin still wasn’t talking.

Dr. Geaux kept telling Calvin all he had to do was “speak up” and “explain himself” and his punishment would end. Of course, this would never happen. Emmet knew that Calvin wasn’t going to say anything until he was good and ready.

And it was getting in the way of their friendship.

Emmet was in a mood all day. The silence at the pizza place was thicker than the deep-dish pepperoni pie they’d ordered.

“Everything okay between you and Calvin, son?” Emmet’s dad asked as they pulled into the driveway.

“Yeah. Fine.”

“Didn’t sound fine. Didn’t sound fine at all at dinner. You were both as quiet as stones. Calvin doesn’t talk much on a good day, but you’re usually up for some enjoyable conversation.”

Emmet sighed. “I don’t know. I guess I’m just tired.”

His dad didn’t press it, which Emmet appreciated.

Even though Calvin was still technically grounded, Dr. Geaux let him come along for their pizza outing every Thursday. Emmet thought it was more because she liked spending time with his dad. Calvin’s secret-keeping shouldn’t interfere with their blossoming relationship.

Just because Emmet was a kid didn’t mean he didn’t get stuff. His dad and Dr. Geaux liked each other. Whatever. He had more important things to worry about.

Apollo was barking madly when they walked up the front steps. This was not unusual. He always howled, yipped, and squeaked whenever they returned from anywhere and he had not been allowed to go along — something he considered a federal crime.

There were four stages of greeting whenever they returned.

First, he would be scratching at the door as it was opened and would jump on Emmet or his dad as they stepped through, barking and yapping, then rolling over on his back for a belly rub as if they’d left him alone for weeks. The fact that they’d been gone less than ninety minutes was lost on him.

Second, he would spring to his feet and begin sniffing their shoes and legs, and then stand on his hind legs and smell their pockets. He was checking to see if they had encountered anything from the animal kingdom that had left its scent on them. Or if they had, by any chance, brought home anything edible. And Apollo had a wide range of things he considered edible.

The third stage would be indignation. Emmet would say, “Hi, buddy!” and reach down to scratch his ears. Apollo would race away a few feet, just out of reach. This was supposed to be Emmet’s punishment for abandoning him. It usually lasted all of ten seconds, until Apollo gave in, raced forward, and entered the fourth stage, which was repeating the entire process all over again.

But this time when Emmet and his dad entered the house, Apollo didn’t engage in his regular routine. He barked in happiness, but in the middle of the first belly rub, sprang to his feet and raced to the back door. He lifted his head and howled. His howl was high-pitched and sounded funny. It was usually reserved for when he spotted a jogger on the street, or the mailman delivered the mail, or an unauthorized leaf had the gall to blow across the front yard.

“What’s gotten into him?” asked Emmet’s dad as they followed him into the kitchen.

“Beats me,” Emmet said. He looked at Apollo’s water dish. It had been full when they left, but was more than half empty now.

“Maybe he really has to go,” he said.

Emmet’s backyard was securely fenced in to keep alligators out. They lived in Florida, after all, a place where you had to consider the possibility that a two-hundred-million-year-old species of killing machine might casually stroll into your backyard if it was left unfenced. Especially if you had pets. People who didn’t live there did not have to think about this. Emmet himself still wasn’t used to it.

The yard had a small stone patio and three cypress trees. Dr. Catalyst had kidnapped Apollo from it not too long ago. Since that happened, they had motion-sensor lights mounted on the wall on either side of the door. Anytime Apollo went outside for his nightly ritual, either Emmet or his dad made sure to watch over him.

Apollo was acting really weird. He was anxious to get outside, running back and forth between Emmet and the door. Emmet nearly tripped over him several times on the way. As he pulled it open the first few inches, with Apollo desperately trying to squirm his way through the tiniest opening, it suddenly registered that the yard lights were shining brightly. They shouldn’t have been, unless something in the backyard … something moving around … had turned them on.

Emmet had his hand on the doorknob. Apollo was still howling. His dad had stopped paying attention and was sorting through the mail. The door was open about a foot wide when something big and brown and furry catapulted into it so hard it knocked him to the ground.

“Emmet!” He heard his dad shout. Or at least he thought it was his dad. He was a little stunned, what with the falling to the ground and banging his head on the floor. Slowly, Emmet raised his head up to see Apollo crouched with his back low to the ground, his teeth bared, and the fur on his back standing almost straight up.

The screen door had saved them. Whatever had launched itself at Emmet and Apollo was now tangled up in the screen. All Emmet could see was a head peeking through the open space where the door had gotten lodged against his feet.

A terrifying head. Or more accurately, giant, sharp teeth that happened to be attached to a head. It had a furry face and a snout and muzzle kind of like a dog. And it alternated between a mewling growl like a cat and a weird laughing sound.

But it was mad and hungry and trying to get inside.

“Apollo! Off! Off!” Emmet heard his dad shout. That was Apollo’s command to stop and stand down. But he was beyond that. Most of the time he obeyed. But this was different. His personal space was about to be invaded by a … giant, toothy … thing. He leapt at the head and was about to land right inside its mouth when Emmet found the strength to reach up and snatch his hind leg, pulling him backward. He was twenty-five pounds of fury.

Emmet kicked hard at the door with his foot and heard the creature snarl in anger. Then his dad flew into his field of vision, throwing his shoulder hard into the door. Whatever was trying to get in yowled in pain, but did not retreat.

“Push!” Emmet shouted. He lifted both feet and jammed them firmly against the door. Luckily it was made of thick, sturdy cypress planks, because whatever this thing was, it was clearly ferocious.

Emmet pushed with his legs as hard as he could, but this was one strong animal. For a second Emmet swore it locked its eyes on his. It howled that weird combination of barking and growling sounds. It was a sound like a cat and dog mixed in a blender. He felt like it stared at him forever, and in that gaze Emmet became truly afraid. The beast’s eyes were cunning. It knew him, and it wanted nothing more than to kill him. When it snarled, its face kind of changed. One moment it looked like some kind of wild cat, and another like a hyena. How could that be?

“Push, Emmet!” his ever-helpful dad yelled.

“I am!” Emmet shouted. He was also holding a very angry little schnoodle by the hind leg, who was doing everything in his power to get loose and jump into the fight.

Even with its neck stuck in the door, the creature refused to withdraw.

“Hang on!” Emmet’s dad yelled. He turned his back to the door and shoved as hard as he could. With his left hand his dad reached over toward the corner where they kept a broom. It was just out of his reach.

“What are you doing?” Emmet yelled at him. His legs were starting to shake. He was losing strength. The creature kept wiggling and squirming, hammering its body against the door, desperate to get in.

Emmet’s dad must have managed to get ahold on the broom, because in the next moment Emmet heard a whistling sound and a loud crack as the broom handle connected with the creature’s snout. It howled in rage. The broomstick hit it again and this time it jerked back and they were able to jam the door shut. Emmet’s dad flipped the lock. The animal was furious, throwing its body at the door over and over, scratching and clawing while Apollo answered each attack with a bark and growl of his own, daring the monster to come inside and face schnoodle justice. Then, eventually, it was silent.

His dad raced to the front door and locked it, then shut the doors to all of the bedrooms, in case it crashed through one of their windows. Emmet wasn’t sure the interior doors would hold it. No, with his luck, it had opposable thumbs and could turn doorknobs.

His dad came back to the kitchen and fell to his knees beside him, cradling Emmet’s head in his lap.

“Are you okay?” he asked.

“Yeah. I think so,” Emmet said.

His head was spinning and his legs were throbbing. Apollo stopped barking and turned his attention to licking Emmet’s face, as if he was trying to revive him. His dad used his cell phone to call 9-1-1. His voice sounded like it was a million miles away.

As Emmet lay there staring up at the ceiling, he could only think of one thing.

How much he hated their backyard.