My Sister Stole My Mate, And I Let Her

Chapter 503: Chapter 503 THE ULTIMATE PUPPET

SERAPHINA’S POV

I came back to myself like I’d been dropped through layers of collapsing glass as the world reassembled itself in fragments.

Cold stone beneath my feet.

The heavy, damp breath of the underground hall.

The cathedral-like chamber rising around me in warped arches of blackened metal and carved stone, lit by those same sickly, ritual-blue veins of light that pulsed faintly through the walls like something half-alive.

And Catherine.

She was exactly where I’d left her, standing at the center of the chamber like she was the sun the universe gravitated around.

But something was wrong.

The smug composure that had once clung to her like perfume was gone.

Her face was tight now, stripped of its certainty, her eyes sharp in a way I had never seen before—actively straining, as if she were listening to something only she could hear.

And she didn’t like what she was hearing.

Her hand was lifted, fingers trembling as she spoke into the empty air beside her.

“No,” she said quickly, voice low and clipped. “That wasn’t what I meant. I said I would stabilize her, not that she would—”

She paused, jaw tightening. “Yes. I understand the consequences. I’m handling it.”

There was no phone in her hand or any visible communication device, but she was speaking anyway, as if the conversation was happening somewhere just outside the range of human perception.

And for the first time since I had known her, Catherine did not look like she was in control of anything.

“I-I know.” Her voice trembled. “I’m sorry. I can fix it.”

The realization landed inside me with slow, incredulous amusement, and a laugh rose in my throat before I could stop it.

It came out sharp, disbelieving, almost disjointed against the oppressive silence of the chamber.

“Well,” I said, my voice echoing against the stone, “this is interesting.”

Catherine’s head snapped toward me instantly. For a heartbeat, her eyes widened, and her face paled, just like that look she’d had back in the dreamscape.

She tried to smother it, forcing steel back into her expression, but it didn’t quite disappear.

“You,” she hissed.

My lips quirked as I straightened and folded my arms. “Me.”

I tilted my head, studying her the way she had always studied me.

“So this is it,” I continued, my tone sharpening with each word as clarity settled into place. “All your scheming, all your perfect little manipulations, all that effort to build me into whatever fantasy you wanted—”

A snort cut me off. “And you’re just someone else’s lackey.”

The words seemed to cut deeper than I expected.

I expected cold denial. I expected her usual posturing.

But her expression cracked into something offended enough to be dangerous.

“You don’t understand what you’re speaking about,” she said coldly. “Shut up.”

Holy shit, I was right.

The presence in the void—the thing that pressed against my mind with that suffocating intimacy, the thing that wanted me—had not been Catherine’s invention. It had not been hers to command or control.

All this time thinking she was the big bad, and she was only a vessel for something else.

Something she evidently feared.

I took a slow step forward, letting my gaze travel over her lazily.

“Who is it?” I asked softly. “Who’s pulling the puppeteer’s strings?”

Red blotches appeared on Catherine’s cheeks. “Stop talking so recklessly!”

And there it was—not authority, not dominance.

Fear.

It was subtle, buried beneath layers of control and rage, but it was there, etched into the foundation of everything she had built.

My smile widened. “Why? Is your boss going to be mad? Is he going to come out of hiding and face me himself?”

Catherine’s hand lowered from the empty air beside her, her attention now fully on me. Whatever conversation she had been having had not ended, but it had been forcibly set aside.

She hissed, voice turning razor-thin, “Do not speak as if you understand forces you cannot comprehend.”

I let out a soft, humorless breath.

“Oh, I understand enough,” I said. “You didn’t build any of this." I waved a hand around the room. "You’re just the ultimate puppet, foolish enough to believe you were in charge of it.”

Something in her snapped at that.

The air in the chamber shifted.

Pressure gathered in the space between us, like the world was tightening its grip around an invisible axis.

The blue veins of light along the walls flickered in response, pulsing unevenly as if reacting to her emotional instability.

“You are a failed variable,” she said quietly, and this time her voice carried something colder than before. “A deviation that should have been corrected long ago.”

Her eyes locked onto mine, and I’d never seen such a potent mixture of hate and rage and fear. “And I will correct you.”

Before I could respond, she moved, and a psychic strike exploded outward from her like an exploding star.

I saw the strike approach in slow motion.

It wasn’t physical. It didn’t travel through air or space in any conventional sense. It simply arrived, a force designed to fracture the mind before the body could even interpret danger.

It rushed towards me with the intent to erase, and I braced myself to meet it.

And then—

Nothing happened.

I blinked.

The pressure dissipated as if it had slid off some invisible barrier.

Catherine froze, jaw slack and eyes wide with confusion and disbelief.

“That—” she began.

Her gaze narrowed sharply, recalibrating, reassessing.

“That’s not possible.”

I exhaled slowly and unclenched my jaw as the echo of her attack faded harmlessly into the stone beneath my feet.

“Performance issues?” I drawled.

“I absorbed all of her power,” Catherine muttered, more to herself than to me. She was staring at my mother’s still figure, a crease between her brows. “You should not have been able to resist that level of direct cognitive disruption.”

A pause.

Then something shifted in her eyes, and I watched understanding dawn there.

Her gaze shifted back to me, but it looked like she was seeing through me, as if she were looking for something embedded deeper beneath my consciousness.

And then she released the faintest tremor in her breath.

“No,” she whispered.

The word wasn’t directed at me. As far as she was concerned, I wasn’t in the room anymore.

She looked like she’d reached a conclusion—and it was an awful one.

“No, no, no,” she spat, glaring at my mother again.

And then it clicked.

“Something went wrong,” I said, my voice soft.

Catherine’s head snapped back toward me. “Shut up.”

I scoffed. “You can’t use her powers to hurt me, can you?”

“Will you just stop talking for a minute!”

I threw my head back, a large bark of laughter escaping me. “You have no idea how fun this entire exchange is for me.”

Catherine ignored me. She was too busy trying to figure out what had gone wrong.

She ran a hand through her hair, and I watched as her perfect composure disintegrated, one delicious crack at a time.

“I absorbed it fully,” she murmured slowly, voice thinning as the implication unfolded. “I should have—”

She took a step forward, her control slipping further with every word. Her eyes were back on my mother.

“She wouldn’t have been able to do that,” Catherine said, more urgently now. “She was broken. She was compliant. She—” Her voice faltered.

And then she stopped as if the realization had struck her mid-sentence. As if something inside her had just rearranged itself into an uglier truth.

Her lips parted.

“No,” she repeated, quieter now, utterly disbelieving. “That’s not possible.”

And then her gaze sharpened with sudden, violent clarity.

Her eyes burned, the last remnants of her restraint dissolving into something volatile.

“You placed a countermeasure inside yourself before the ritual began,” she accused my mother as if she could hold a conversation.

Silence.

Catherine’s voice rose sharply. “You shouldn’t have been able to do that. You’re not a witch; you couldn’t cast such a spell on your own.”

Her hands trembled, rage pouring out of her in waves. And then she froze, as if another puzzle piece had clicked into place.

Her head tilted, and when she spoke again, her voice was as sharp and cold as icicles.

“There’s a traitor,” she announced.

The words echoed through the chamber like a declaration of war.

Her eyes locked onto me again, pupils dilated and brows drawn so tight they nearly met. Her mouth was set in a trembling line, the tension radiating off her like static.

“Someone tampered with your mother’s powers, so I can’t use them to hurt you or any of her bloodline.”

A small breath escaped me. “Looks like you need to get your house in order, Catherine.”

Her eyes narrowed, and her lips pulled into a sinister smile that sent a chill through me.

“Oh, don’t worry about that. I will find them and deal with them later.”

The air around her began to change.

Not just pressure or psychic force.

Something deeper. Something layered beneath reality itself began to stir, as if responding to a signal.

The blue veins along the walls flared violently, pulsing brighter, faster, like a weak heart suddenly defibrillated.

Catherine’s expression shifted into something that no longer resembled calculation or manipulation.

It resembled invocation.

“But first, I’m going to do away with you, once and for all.”

I scoffed. “With what?”

Her gaze darkened.

The temperature in the chamber seemed to drop.

Something vast pressed closer behind her, and the room felt simultaneously smaller and larger.

“You silly, scornful girl,” she scoffed. “Margaret’s power is but a drop in the ocean.”

Her head tilted upward, and her voice softened—not in gentleness, but in submission.

“Malachar,” she whispered, and an involuntary full-body shudder rolled through me. “Grant me full access.”

The air crackled with energy.

And something began to answer.