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The Diabolic

Book #1 of The Diabolic

About The Book

“The perfect kind of high-pressure adventure.” —
A New York Times bestseller!

Red Queen meets The Hunger Games in this epic novel about what happens when a senator’s daughter is summoned to the galactic court as a hostage, but she’s really the galaxy’s most dangerous weapon in disguise.

A Diabolic is ruthless. A Diabolic is powerful. A Diabolic has a single task: Kill in order to protect the person you’ve been created for.

Nemesis is a Diabolic, a humanoid teenager created to protect a galactic senator’s daughter, Sidonia. The two have grown up side by side, but are in no way sisters. Nemesis is expected to give her life for Sidonia, and she would do so gladly. She would also take as many lives as necessary to keep Sidonia safe.

When the power-mad Emperor learns Sidonia’s father is participating in a rebellion, he summons Sidonia to the Galactic court. She is to serve as a hostage. Now, there is only one way for Nemesis to protect Sidonia. She must become her. Nemesis travels to the court disguised as Sidonia—a killing machine masquerading in a world of corrupt politicians and two-faced senators’ children. It’s a nest of vipers with threats on every side, but Nemesis must keep her true abilities a secret or risk everything.

As the Empire begins to fracture and rebellion looms closer, Nemesis learns there is something more to her than just deadly force. She finds a humanity truer than what she encounters from most humans. Amidst all the danger, action, and intrigue, her humanity just might be the thing that saves her life—and the empire.


The Diabolic


SIDONIA had made a dangerous mistake.

She was carving a statue out of a great stone slab. There was something mesmerizing about the swiping and flashing of her laser blade, bright against the dark window overlooking the starscape. She never aimed the blade where I expected, but somehow she always produced an image in the stone that my own imagination could never have conjured. Today it was a star gone supernova, a scene from Helionic history depicted vividly in rock.

Yet one swipe of her blade had extracted too large a chunk from the base of the sculpture. I saw it at once and jumped to my feet, alarm prickling through me. The structure was no longer stable. At any moment, that entire statue was going to come crashing down.

Donia knelt to study the visual effect she’d created. Oblivious to the danger.

I approached quietly. I didn’t want to warn her—it might startle her into jerking or jumping, and cutting herself with the laser. Better to rectify the situation myself. My steps drew me across the room. Just as I reached her, the first creak sounded, fragments of dust raining down from above her as the statue tilted forward.

I seized Donia and whipped her out of the way. A great crashing exploded in our ears, dust choking the stale air of the art chamber.

I wrested the laser blade from Donia’s hand and switched it off.

She pulled free, rubbing at her eyes. “Oh no! I didn’t see that coming.” Dismay slackened her face as she looked over the wreckage. “I’ve ruined it, haven’t I?”

“Forget the statue,” I said. “Are you hurt?”

She glumly waved off my question. “I can’t believe I did that. It was going so well. . . .” With one slippered foot, she kicked at a chunk of broken stone, then sighed and glanced at me. “Did I say thanks? I didn’t. Thanks, Nemesis.”

Her thanks did not interest me. It was her safety that mattered. I was her Diabolic. Only people craved praise.

Diabolics weren’t people.

We looked like people, to be sure. We had the DNA of people, but we were something else: creatures fashioned to be utterly ruthless and totally loyal to a single individual. We would gladly kill for that person, and only for them. That’s why the elite imperial families eagerly snatched us up to serve as lifelong bodyguards for themselves and their children, and to be the bane of their enemies.

But lately, it seemed, Diabolics were doing their jobs far too well. Donia often tapped into the Senate feed to watch her father at work. In recent weeks, the Imperial Senate had begun debating the “Diabolic Menace.” Senators discussed Diabolics gone rogue, killing enemies of their masters over small slights, even murdering family members of the child they were assigned to protect to advance that child’s interests. We were proving more of a threat to some families than an asset.

I knew the Senate must have come to a decision about us, because this morning, the Matriarch had delivered a missive to her daughter—one directly from the Emperor. Donia had taken a single look at it and then thrown herself into carving.

I’d lived with her for nearly eight years. We’d virtually grown up side by side. She only grew silent and distracted like this when worried about me.

“What was in the missive, Donia?”

She fingered a slab of the broken statue. “Nemesis . . . they banned Diabolics. Retroactively.”

Retroactively. That meant current Diabolics. Like me.

“So the Emperor expects you to dispose of me.”

Donia shook her head. “I won’t do it, Nemesis.”

Of course she wouldn’t. And then she’d be punished for it. An edge crept into my voice. “If you can’t bring yourself to be rid of me, then I’ll take the matter into my own hands.”

“I said I won’t do it, Nemesis, and neither will you!” Her eyes flashed. She raised her chin. “I’ll find another way.”

Sidonia had always been meek and shy, but it was a deceptive appearance. I’d long ago learned there was an undercurrent of steel within her.

Her father, Senator von Impyrean, proved a help. He nursed a powerful animosity toward the Emperor, Randevald von Domitrian.

When Sidonia pleaded for my life, a glimmer of defiance stole into the Senator’s eyes. “The Emperor demands her death, does he? Well, rest easy, my darling. You needn’t lose your Diabolic. I’ll tell the Emperor the death has been carried out, and that will be the end of the matter.”

The Senator was mistaken.

Like most of the powerful, the Impyreans preferred to live in isolation and socialize only in virtual spaces. The nearest Excess—those free humans scattered on planets—were systems away from Senator von Impyrean and his family. He wielded his authority over the Excess from a strategic remove. The family fortress orbited an uninhabited gas giant ringed by lifeless moons.

So we were all startled weeks later when a starship arrived out of the depths of space—unannounced, unheralded. It had been dispatched by the Emperor under the pretext of “inspecting” the body of the Diabolic, but it was no mere inspector onboard.

It was an Inquisitor.

Senator von Impyrean had underestimated the Emperor’s hostility toward the Impyrean family. My existence gave the Emperor an excuse to put one of his own agents in the Impyrean fortress. Inquisitors were a special breed of vicar, trained to confront the worst heathens and enforce the edicts of the Helionic religion, often with violence.

The Inquisitor’s very arrival should have terrified the Senator into obedience, but Sidonia’s father still circumvented the will of the Emperor.

The Inquisitor had come to see a body, so a body he was shown.

It simply wasn’t mine.

One of the Impyreans’ Servitors had been suffering from solar sickness. Like Diabolics, Servitors had been genetically engineered for service. Unlike us, they didn’t need the capacity to make decisions, so they hadn’t been engineered to have it. The Senator took me to the ailing Servitor’s bedside and gave me the dagger. “Do what you do best, Diabolic.”

I was grateful he’d sent Sidonia to her chambers. I wouldn’t want her to see this. I sank the dagger under the Servitor’s rib cage. She didn’t flinch, didn’t try to flee. She gazed at me through blank, empty eyes, and then a moment later she was dead.

Only then was the Inquisitor allowed to dock with the fortress. He made a cursory inspection of the body, pausing over it merely to note, “How odd. She appears . . . freshly dead.”

The Senator stood bristling at his shoulder. “The Diabolic has been dying of solar sickness for several weeks now. We’d just decided to end her suffering when you arrived in the system.”

“Contrary to what your missive said,” the Inquisitor stated, swinging on him. “You claimed the death had already been carried out. Now that I see her, I wonder at her size. She’s rather small for a Diabolic.”

“Now you question the body, too?” roared the Senator. “I tell you, she was wasting away for weeks.”

I watched the Inquisitor from the corner. I wore a new Servitor’s gown, my size and musculature hidden beneath voluminous folds. If he saw through the ruse, then I would kill him.

I hoped it wouldn’t come to that. Concealing an Inquisitor’s death might prove . . . complicated.

“Perhaps if your family was more respectful of the Living Cosmos,” the Inquisitor remarked, “your household would have been spared a ghastly affliction like solar sickness.”

The Senator ripped in an angry breath to reply, but at that moment the Matriarch darted forward from where she’d been lurking in the doorway. She seized her husband’s arm, forestalling him.

“How right you are, Inquisitor! We are immensely grateful for your insight.” Her smile was gracious, for the Matriarch didn’t share her husband’s eagerness to defy the Emperor.

She’d felt imperial wrath firsthand at a young age. Her own family had displeased the Emperor, and her mother had paid the price. Now she appeared electric with anxiety, her body quivering with eagerness to placate their guest.

“I’d be ever so pleased if you’d observe our services tonight, Inquisitor. Perhaps you can note what we are doing wrong.” Her tone dripped with sweetness, the sort that sounded odd in her usual acrid voice.

“I would be glad to do so, Grandeé von Impyrean,” replied the Inquisitor, now gracious. He reached out to draw her knuckles to his cheek.

She pulled away. “I’ll go make the arrangements with our Servitors. I’ll take this one now. You—come.” She jerked her head for me to accompany her.

I didn’t want to leave the Inquisitor. I wanted to watch his every movement, observe his every expression, but the Matriarch had left me no choice but to follow her as a Servitor would. Our steps brought us out of the chamber, far from the Inquisitor’s sight. The Matriarch picked up her pace, and I did as well. We wound together down the corridor toward the Senator’s chambers.

“Madness,” she muttered. “It’s madness to take this risk right now! You should be lying dead before that Inquisitor, not walking here at my side!”

I cast her a long, considering look. I’d gladly die for Donia, but if it came to my life or the Matriarch’s, I’d put myself first. “Do you intend to tell the Inquisitor what I am?”

Even as I spoke, I visualized the blow I’d use to kill her. A single strike to the back of the head. . . . No need to risk her screaming. Donia might emerge from her chambers if she heard anything. I’d hate to murder her mother in front of her.

The Matriarch had the survival instinct her husband and daughter lacked. Even my mild tone sent terror skittering across her face. The next moment it vanished so swiftly that I wondered whether I’d imagined it. “Of course not. The truth would condemn us all now.”

So she would live. My muscles relaxed.

“If you’re here,” she said darkly, “then you’ll make yourself useful to us. You’ll help me conceal my husband’s work before that Inquisitor inspects his chambers.”

That I could do. We plunged into the Senator’s study, where the Matriarch hiked up her gown and shuffled through the debris strewn about the room—blasphemous database fragments that would instantly condemn this entire family if the Inquisitor laid eyes on them.

“Quickly now,” she said, gesturing for me to start swiping them up.

“I’ll take them to the incinerator—”

“Don’t.” Her voice was bitter. “My husband will simply use their destruction as an excuse to acquire more. We simply need to clear these from sight for now.” She twisted her fingers in a crack in the wall, and the floor slid open to reveal a hidden compartment.

Then she settled in the Senator’s chair, fanning herself with her hand as I heaved armful after armful of shattered fragments of what looked like computer debris and data chips into the compartment. The Senator passed days in here, repairing whatever he could salvage, uploading information into his personal database. He avidly read the materials and often discussed them with Sidonia. Those scientific theories, those technological blueprints. All blasphemous. All insults against the Living Cosmos.

I stashed the Senator’s personal computer in with the debris, and then the Matriarch crossed to the wall again and twisted her finger in the nook. The floor slid closed. I heaved the Senator’s desk over so it covered the hidden compartment.

I straightened again to find the Matriarch watching me narrowly. “You would have killed me back in the hallway.” Her glittering eyes challenged me to deny it.

I didn’t. “You know what I am, madam.”

“Oh yes, I do.” Her lips twisted. “Monster. I know what goes on behind those cold, soulless eyes of yours. This is exactly why Diabolics have been banned—they protect one and pose a threat to all others. You must never forget that Sidonia needs me. I’m her mother.”

“And you must never forget that I’m her Diabolic. She needs me more.”

“You cannot possibly fathom what a mother means to a child.”

No. I couldn’t. I’d never had one. All I knew was that Sidonia was safer with me than with anyone else in this universe. Even her own kin.

The Matriach loosed an unpleasant laugh. “Ah, but why even debate you on this? You could no more understand family than a dog could compose poetry. No, what matters is, you and I share a cause. Sidonia is kindhearted and naive. Outside this fortress, in the wider Empire . . . perhaps a creature like you will be the very thing my daughter requires to survive. But you will never—never—speak to anyone of what we’ve done today.”


“And if anyone seems ready to find out we’ve spared our Diabolic, then you will take care of the problem.”

The very thought sent a sizzling, protective anger through me. “Without hesitation.”

“Even if taking care of it”—her eyes were sharp and birdlike—“starts with yourself.”

I didn’t condescend to answer. Of course I would die for Sidonia. She was my entire universe. I loved nothing but her and valued nothing but her existence. Without her, there was no reason for me to exist.

Death would be a mercy compared to that.

About The Author

Photograph (c) Chelsea Dier

S.J. Kincaid is the New York Times bestselling author of The Diabolic trilogy. She originally wanted to be an astronaut, but a dearth of mathematical skills made her turn her interest to science fiction instead. Her debut novel, Insignia, was shortlisted for the Waterstones Children’s Book Prize. Its sequels, Vortex and Catalyst, have received starred reviews from Kirkus Reviews and Booklist. She’s chronically restless and has lived in California, Alabama, New Hampshire, Oregon, Illinois, and Scotland with no signs of staying in one place anytime soon. Find out more at

Product Details

  • Publisher: Simon & Schuster Books for Young Readers (August 29, 2017)
  • Length: 432 pages
  • ISBN13: 9781481472685
  • Grades: 9 and up
  • Ages: 14 - 99
  • Lexile ® HL810L The Lexile reading levels have been certified by the Lexile developer, MetaMetrics®

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Raves and Reviews

"Exploring what it is to question society’s definition of what you are and who you should be...the first-person narration makes the story immediate, and the political plotline could yield some thought-provoking discussion."

– Booklist, August 2016

"Philosophical, twisty, and addictive."

– Kirkus Reviews, August 2016

"Kincaid has crafted incredible characters who readers can relate to and care for...these protagonists and the complex setting will thrill the YA audience. VERDICT Fans of Marissa Meyer’s “The Lunar Chronicles” will enjoy Kincaid’s latest. This story of friendship, love, loss, suspense, and galactic beings will grab the attention of sci-fi fans and general readers alike."

– School Library Journal, September 2016

Awards and Honors

  • YALSA Teens Top Ten (TTT) Nominee
  • TAYSHAS Reading List (TX)
  • ALA/YALSA Best Fiction for Young Adults - Top Ten
  • Wisconsin State Reading Association's Reading List
  • Eliot Rosewater Indiana High School Book Award Nominee

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More books in this series: The Diabolic