The cat was running.

Milo Finch was chasing it.

Clara Quibble was chasing Milo.

Mr. Percival Puddlewick was chasing Clara.

Edgar Bell was chasing Mr. Puddlewick.

And somewhere behind them, Professor Archibald Tickwell was presumably chasing everyone else.

It was, in short, a perfectly organized investigation.

“Stop that cat!” Milo shouted.

The cat did not stop.

“Come back here!”

The cat continued running.

“You are under arrest!”

The cat disappeared around a corner.

Milo stopped.

Clara crashed into him.

Mr. Puddlewick crashed into Clara.

Edgar crashed into Mr. Puddlewick.

Everyone fell into a heap.

The cat sat on a stone wall and watched them.

Milo slowly lifted his head.

“Did anyone get its license plate?”

Clara pushed herself up.

“It’s a cat.”

“Exactly. Very suspicious.”

The cat yawned.

Milo pointed at it.

“Look at that attitude.”

Clara stood up.

“Milo, we’ve just discovered a secret underground chamber filled with thirteen mysterious gears, Professor Tickwell has disappeared twice, and something underneath Bellwick is apparently waking up.”

“Yes.”

“And you’re worried about the cat?”

“Have you seen its eyes?”

Clara stared at him.

“They’re green.”

“Criminal green.”

“They’re just green.”

“That’s what they want you to think.”

The cat suddenly jumped down from the wall and disappeared into an alley.

Milo ran after it.

Clara grabbed his coat.

“No.”

“But—”

“No.”

“The cat—”

“No.”

“It knows something!”

“Maybe.”

Milo looked hopeful.

“Then we should follow it.”

“We don’t know where it went.”

Milo pointed at the alley.

“That’s where detectives come in.”

“How?”

“We follow mysterious cats.”

Clara sighed.

“Fine.”

The alley was narrow and dark.

They followed the cat’s paw prints through the dust.

The trail ended at a small wooden door.

Milo examined it.

“Interesting.”

Clara looked at him.

“What?”

“It’s a door.”

“Yes.”

“Very suspicious.”

“Everything is suspicious to you.”

Milo nodded proudly.

“That’s why I’m a detective.”

He tried the handle.

Locked.

Clara reached into her pocket.

“I have the golden key.”

Milo’s eyes widened.

“Excellent.”

She inserted it into the lock.

CLICK.

The door opened.

Milo stared at her.

“You’re becoming dangerously competent.”

“Thank you.”

“Stop it.”

They entered.

Inside was a tiny room filled with boxes.

Milo immediately sneezed.

“ACHOO!”

Clara jumped.

“What was that?”

“A sneeze.”

“I thought someone attacked you.”

“No. My nose is simply investigating the dust.”

Clara began searching through the boxes.

Milo noticed something.

“Clara.”

“What?”

“Look at this.”

He held up a small wooden photograph frame.

Inside was an old photograph.

It showed a group of people standing beside the clock tower.

At the center stood a young Samuel Bell.

Beside him was another man.

Milo frowned.

“Who is that?”

Clara examined the photograph.

“I don’t know.”

Milo turned the frame around.

Written on the back were five words:

THE FOUNDERS OF THE THIRTEENTH HOUR.

Clara’s expression changed.

“The Thirteenth Hour.”

Milo nodded.

“I don’t like the sound of that.”

“Why?”

“Because the first twelve hours are already enough trouble.”

Clara ignored him.

She looked through the boxes.

Inside were old newspapers.

One headline caught her attention.

BELLWICK CLOCK TOWER CLOSED AFTER STRANGE INCIDENT

The newspaper was dated 1891.

Clara read aloud.

“Bellwick residents reported hearing strange sounds beneath the town shortly after midnight.”

Milo leaned closer.

“What kind of sounds?”

Clara continued.

“According to witnesses, a deep mechanical noise was heard beneath the clock tower. The town’s founder, Samuel Bell, refused to explain the incident.”

Milo stared at the article.

“Keep reading.”

Clara did.

“Three days later, Samuel Bell disappeared.”

Milo’s face became serious.

“What happened to him?”

“Nobody knows.”

Milo looked at the photograph again.

“Then why is his grave here?”

Clara frowned.

“Maybe he died later.”

“Maybe.”

Milo looked at the photograph.

“Or maybe…”

He paused.

Clara waited.

Milo pointed dramatically.

“He’s still alive.”

Clara stared at him.

“Milo.”

“Yes?”

“Samuel Bell lived in the nineteenth century.”

“So?”

“He would be over one hundred and fifty years old.”

Milo thought about it.

“That’s old.”

“Very.”

“Suspiciously old.”

Clara groaned.

Suddenly, a noise came from the other side of the room.

SCRATCH.

SCRATCH.

Milo froze.

“Did you hear that?”

“Yes.”

SCRATCH.

SCRATCH.

Milo slowly reached for his police whistle.

Clara grabbed his hand.

“Don’t.”

“Why?”

“You blew it last time.”

“Exactly.”

“And?”

“It worked.”

“You screamed when it went off.”

“It was loud.”

The scratching continued.

Milo took a deep breath.

“Prepare yourself.”

“For what?”

“Whatever is behind that box.”

Clara picked up a broom.

Milo grabbed a wooden spoon.

Clara stared at him.

“Why do you have a spoon?”

“It’s my weapon.”

“You’re holding it backward.”

Milo looked down.

“That’s why it feels uncomfortable.”

The scratching became louder.

SCRATCH!

SCRATCH!

SCRATCH!

Milo suddenly kicked the box.

It fell over.

A tiny creature jumped out.

“AAAAAAAH!”

Milo screamed.

The creature screamed.

Clara screamed.

The creature ran.

Milo chased it.

Then stopped.

“It was a mouse.”

Clara stared at him.

“You screamed because of a mouse.”

“I was surprised.”

“You screamed like the building was on fire.”

“It had an aggressive face.”

“It was a mouse.”

“Exactly. They’re small, fast, and organized.”

Clara shook her head.

Then she noticed something under the box.

A second photograph.

This one showed the same group of people.

But there was something strange.

The face of one person had been scratched out.

Clara held it up.

“Someone doesn’t want us to know who this is.”

Milo looked closer.

“Can you tell who it was?”

“No.”

Milo pointed at the back.

“Look.”

Written in faded ink were four words:

HE BUILT THE FIRST GEAR.

Clara stared.

“Who?”

Before Milo could answer, the room shook.

BOOM!

Dust fell from the ceiling.

Milo grabbed Clara.

“Earthquake!”

Another BOOM!

Milo grabbed Mr. Puddlewick.

“Earthquake!”

Clara shouted, “Mr. Puddlewick isn’t even here!”

Milo looked at the man in his arms.

He was holding a coat rack.

“Sorry.”

The ground shook again.

This time, a crack appeared in the floor.

From beneath it came a deep mechanical sound.

GRRRRRRRRRRRR.

Clara’s face went pale.

“The mechanism.”

Milo swallowed.

“What mechanism?”

“The one beneath Bellwick.”

The sound grew louder.

Then the entire building began to tremble.

Milo grabbed the photograph.

“We’re leaving.”

Clara nodded.

“Agreed.”

They ran outside.

The moment they reached the street, the ground stopped shaking.

The town was silent.

Then every clock in Bellwick began ringing.

DONG.

DONG.

DONG.

Milo counted.

“One…”

DONG.

“Two…”

DONG.

“Three…”

Clara grabbed his arm.

“Don’t count.”

“Why?”

“You know what happens.”

Milo stopped.

Everyone in the town watched the clock tower.

DONG.

Twelve.

Silence.

Milo held his breath.

Then…

DONG.

Thirteen.

The clock laughed.

“HAAAAA-HA-HA-HA!”

A scream came from the crowd.

Then another.

Then someone shouted:

“RUN!”

Everyone ran.

Milo looked around.

“Why is everyone running?”

Clara pointed behind him.

Milo turned.

A giant metal hand had emerged from the ground.

Milo’s mouth fell open.

“That is new.”

The hand slowly disappeared.

The street became quiet.

Milo stared.

“Did anyone else see that?”

Clara nodded.

“Yes.”

Mr. Puddlewick appeared from behind a tree.

“Definitely.”

Edgar came running toward them.

“My cat is missing!”

Milo turned.

“Forget your cat!”

“Never!”

“It’s probably responsible for this!”

Edgar looked offended.

“My cat is a respectable citizen.”

“Your cat opened a secret door.”

“He’s talented.”

“He stole a golden gear!”

“He’s curious.”

“He may be working for a criminal organization!”

“He’s a cat.”

Milo opened his mouth.

Then closed it.

“Fair point.”

Clara suddenly noticed something.

“Where is Professor Tickwell?”

Everyone looked around.

He was gone.

Again.

Milo stared at the empty street.

“That man disappears too often.”

Clara nodded.

“Maybe he’s the thief.”

Milo shook his head.

“No.”

“Why not?”

“Because he’s too obvious.”

Clara stared.

“You accused him twice.”

“Exactly.”

Milo turned toward the clock tower.

“We need answers.”

They returned to the tower.

This time, the main doors were open.

Inside, everything looked different.

The gears had stopped moving.

The walls were covered in black marks.

And at the center of the floor was a large circular symbol.

The same symbol that appeared on the golden key.

Clara crouched beside it.

“Look.”

There were thirteen small spaces around the symbol.

Twelve were empty.

One contained a tiny golden gear.

Milo stared.

“Where did that come from?”

Clara shook her head.

“I don’t know.”

Milo looked around.

“We need to find the professor.”

A voice came from the staircase.

“Looking for me?”

Milo jumped.

Professor Tickwell stood above them.

This time, he was holding something.

A black feather.

Milo immediately pointed.

“You’re the mysterious bird!”

Professor Tickwell stared at him.

“What?”

“Nothing.”

Clara stepped forward.

“Professor, we need answers.”

Tickwell looked at the symbol.

“You found the chamber.”

“Yes.”

“You found the gears.”

“Yes.”

“You saw the mechanism.”

“Yes.”

The professor sighed.

“Then there’s no point hiding the truth anymore.”

Milo leaned forward.

“Excellent.”

Professor Tickwell slowly walked down the stairs.

“More than one hundred years ago, Samuel Bell discovered something beneath Bellwick.”

“What?”

“An ancient machine.”

“Who built it?”

“We don’t know.”

“Why was it built?”

“We don’t know.”

“What does it do?”

Professor Tickwell stopped.

“That’s the problem.”

Milo frowned.

“What’s the problem?”

“We don’t know.”

Milo looked at Clara.

“He’s not very helpful.”

Clara nodded.

Professor Tickwell continued.

“The machine contains thirteen gears.”

“We know.”

“Each gear controls a different part of the mechanism.”

“Like what?”

“Time.”

Milo blinked.

“What?”

“Time.”

Clara’s expression changed.

“You mean the machine controls time?”

“Not exactly.”

“Then what does it do?”

Tickwell looked toward the clock.

“It remembers it.”

Milo stared.

Clara stared.

The professor continued.

“The machine beneath Bellwick was built to record every moment that happens in this town.”

Milo frowned.

“Why?”

“No one knows.”

“Then why steal the gears?”

Tickwell’s face became serious.

“Because the gears are not being stolen.”

Milo froze.

“Then what is happening?”

The professor looked directly at him.

“They are returning.”

Silence.

Clara stepped closer.

“Returning to whom?”

Professor Tickwell looked at the golden gear.

“To the machine.”

Milo’s eyes narrowed.

“Who is putting them back?”

The professor didn’t answer.

Milo stepped forward.

“Professor.”

No answer.

“Professor!”

Suddenly, the clock tower doors slammed shut.

BANG!

Milo turned.

A shadow moved across the wall.

Someone was inside the tower.

Someone besides them.

Clara whispered.

“There’s someone here.”

Milo nodded.

They heard footsteps.

Slow.

Careful.

Coming from above.

Clack.

Clack.

Clack.

Milo raised his wooden spoon.

Clara stared at it.

“You’re still carrying that?”

“Yes.”

“Why?”

“It’s lucky.”

“How?”

“I haven’t died yet.”

The footsteps stopped.

Then a figure appeared at the top of the staircase.

It was a woman.

She wore a long gray coat.

Her face was hidden beneath a wide black hat.

Milo stepped forward.

“Identify yourself.”

The woman smiled.

“You already know me.”

Milo frowned.

“I don’t.”

“You do.”

Clara stared at the woman.

Then her eyes widened.

“Milo.”

“What?”

“Look at her necklace.”

The woman wore a silver pendant.

A circle.

Thirteen lines.

The same symbol.

Milo pointed.

“You’re part of the Thirteenth Hour.”

The woman smiled.

“Very good.”

“Who are you?”

She removed her hat.

Milo stared.

Clara stared.

Professor Tickwell stepped backward.

Because the woman was not a stranger.

She was Bellwick’s mayor.

Mayor Beatrice Bumble.

Mrs. Agnes Bumble’s older sister.

Milo’s mouth fell open.

“The mayor?”

The mayor smiled.

“Yes.”

Milo pointed at her.

“You’re the thief!”

“No.”

“You’re the criminal mastermind!”

“No.”

“You’re the mysterious bird!”

“WHAT IS WRONG WITH YOU?”

Milo lowered his spoon.

“Sorry.”

The mayor walked down the stairs.

“I am not your enemy.”

“Then why are you here?”

“To warn you.”

“About what?”

The mayor looked at the clock.

“The thirteenth gear.”

Clara’s face went pale.

“What about it?”

The mayor whispered:

“It has been found.”

Milo swallowed.

“Where?”

The mayor pointed toward the floor.

“Below us.”

A deep sound came from beneath the tower.

BOOM.

BOOM.

BOOM.

The entire tower shook.

The mayor stepped back.

“It has awakened.”

The clock began ticking.

Faster.

Faster.

Faster.

Then every clock in the tower suddenly stopped.

Milo looked at Clara.

“What happens now?”

The mayor looked terrified.

“Now…”

She pointed toward the floor.

“…we find out who has been controlling the machine.”

A loud metallic click echoed beneath them.

Then a hidden door opened.

A staircase descended into darkness.

Milo stared.

Clara stared.

Professor Tickwell stared.

The mayor stared.

Nobody moved.

Then Milo raised his hand.

“I have a question.”

Everyone looked at him.

“Yes?” Clara asked.

“Does anyone have a less dangerous plan?”

Nobody answered.

Milo sighed.

“Fine.”

He started walking toward the staircase.

Clara followed.

The mayor followed Clara.

Professor Tickwell followed the mayor.

Suddenly, Edgar Bell appeared from behind a clock.

Everyone screamed.

Edgar blinked.

“What?”

Milo pointed at him.

“How did you get here?”

Edgar shrugged.

“I followed my cat.”

“Where is your cat?”

Edgar pointed down the staircase.

Everyone looked.

Two green eyes stared back from the darkness.

The cat meowed.

Then it disappeared.

Milo sighed.

“Of course.”

They began descending.

Step by step.

Deeper and deeper beneath Bellwick.

The walls became colder.

The air became heavier.

Then they reached a massive underground chamber.

At its center stood an enormous machine.

It was made of iron, gold, and hundreds of moving gears.

Thirteen large golden slots surrounded it.

Twelve gears were already inside.

One slot remained empty.

Milo stared.

“That’s the thirteenth gear.”

Clara nodded.

“Where is it?”

A voice answered from the darkness.

“Right here.”

Everyone turned.

A figure stepped into the light.

Milo’s eyes widened.

The figure was holding the missing gear.

And standing beside him was…

Professor Archibald Tickwell.

Milo stared at the professor.

Then at the figure.

Then back at the professor.

“Wait.”

Clara whispered.

“Milo.”

“Yes?”

“I think we have a problem.”

Milo nodded.

“Yes.”

He pointed at the mysterious figure.

“He’s holding the gear.”

Then he pointed at Professor Tickwell.

“And the professor is standing with him.”

Then he looked at the mayor.

“And the mayor is apparently involved.”

Then he looked at Edgar.

“His cat is also suspicious.”

Edgar frowned.

“Leave my cat out of this.”

Milo raised his spoon.

“Nobody move!”

The mysterious figure laughed.

Then he stepped forward.

Milo’s face suddenly changed.

Because he recognized him.

It was the man from the old photograph.

The man whose face had been scratched away.

The man who had supposedly disappeared more than one hundred years ago.

The man who had built the first gear.

Milo whispered:

“Samuel Bell.”

The old man smiled.

“Finally.”

The machine behind him began to move.

And somewhere above them, the clock tower began laughing.

Not twelve times.

Not thirteen.

But fourteen.

DONG.

Milo stared upward.

Clara whispered:

“That’s impossible.”

Samuel Bell smiled.

“No.”

He held up the thirteenth gear.

“It’s only the beginning.”

The chamber went completely dark.

And when the lights returned…

Samuel Bell was gone.

So was the thirteenth gear.

But on the floor, written in fresh black ink, was a new message.

THE NEXT PERSON TO DISAPPEAR WILL BE THE DETECTIVE.

Milo stared at the words.

Then slowly looked at Clara.

Clara looked back.

“Milo.”

“Yes?”

“I think that’s you.”

Milo nodded.

“Yes.”

He took one step backward.

Then another.

Then he turned around and ran.

Clara shouted after him.

“Where are you going?”

Milo shouted back:

“TO RESIGN!”

And for the first time in one hundred and fifty years…

The ancient machine beneath Bellwick began to laugh.