The Billionaire's Heir I Never Knew Was Mine

Zoey stepped out of her parents’ bedroom, closing the door behind her with a soft click. She exhaled deeply as if trying to shake off the lingering weight of the conversation inside.

But the relief didn’t last.

She nearly tripped over her own feet when she saw Zachary standing right in front of her.

He hadn’t made a sound.

Dressed sharply in a dark suit, he looked completely out of place in the quiet hallway of their home. Too composed. Too still. Like he had been waiting there long enough to become part of the shadows.

He looked less like a son visiting his parents and more like a guard stationed to eliminate any threat.

The way his eyes fixed on her made Zoey instinctively straighten her back.

"Damn you, Zach! You really startled me..." Zoey’s voice came out sharper than she intended. "Are you waiting for me?" 𝘧𝘳𝘦ℯ𝓌𝘦𝒷𝘯𝑜𝑣𝘦𝓁.𝒸𝘰𝓂

"Why are you surprised?" he asked.

Zachary leaned casually against the wall, but there was nothing relaxed about him. His gaze was sharp, scanning her as if she had just committed a crime.

"Did you do something horrible in there?" he continued, his voice calm but edged with something that made the air feel tighter.

Zoey blinked, then narrowed her eyes at him.

"Excuse me? The only terrible thing in that room is how long Mom made me sit there and listen to her complain about your work schedule."

Zachary didn’t react, which only annoyed her more.

Zoey clenched her hand, irritation rising, but then something flickered across her mind. A smile slowly curved her lips, turning sly.

"Oh, right," she said, as if something had just clicked. "Bro, you need to introduce me to your girlfriend. If I’m not mistaken, her name is Sienna..."

She said it lightly, teasing—but she regretted it the moment the words left her mouth.

Zachary didn’t move. He didn’t even bother pretending to care. He just looked at her as if she had said something utterly insignificant.

Zoey’s smile twitched. She crossed her arms, refusing to back down.

"Bro, if you don’t tell me," she continued, her tone still light but laced with a threat, "I’ll tell Mom and Dad about—"

She didn’t get to finish.

In the next second, her wrist was caught in a firm grip.

Zoey gasped as Zachary’s hand tightened around her wrist, pulling her toward him in one swift motion. It was fast. Controlled. Completely unexpected.

"What the hell are you trying to do—"

He pulled harder, throwing off her balance. His face was suddenly much closer to hers, his expression colder than before.

For a fleeting moment, Zoey could almost believe he enjoyed seeing the fear on her face.

"Little sister." His voice was sharp enough to make her flinch. "Never threaten me about her."

Zoey’s brows knit together, confusion quickly turning into irritation. "Zach! Let go of my hand. It hurts—"

But Zachary ignored her.

"Or you won’t be able to bear the consequences."

The pressure on her wrist increased—just enough to hurt. Not enough to injure, but more than enough to remind her exactly who she was dealing with.

"Let go of my hand, Zach!" Zoey snapped, her voice rising without her realizing it. "It hurts... a lot!"

He didn’t move. Didn’t loosen his grip. His eyes only darkened.

"Promise me," he demanded.

"Promise you what?" Zoey shot back, frustration spiking. "Who the hell is she? Is she Skylar’s mom? Why are you acting like—ah—Zach, it hurts! Stop, or I’ll call Dad!"

"Do that," he said coldly, "and I might snap and accidentally break your wrist. You will promise me."

Zoey froze, staring at him.

This was her brother. Her twin. The same person who used to argue with her over the last piece of cake.

And yet right now, he looked like someone she didn’t fully recognize.

"Alright, alright... I promise. I promise," she said quickly, the pain and tension finally forcing her to give in. "I won’t talk about her. Let go of my hand!"

For a moment, Zachary didn’t move.

Then, after a few seconds, he finally released her.

Its suddenness made Zoey stumble back. She nearly lost her balance before catching herself against the wall. She immediately glared at him, rubbing her wrist.

"You’re unbelievable, Zach..." she snapped, anger sharpening her voice. "Hurting your own sister for someone like her?"

Zachary didn’t respond. He simply looked at her, his expression unreadable.

Then, in a low voice that carried more weight than any shout, he said, "Zoey, this is my last warning. If I hear you talk about her again, you will regret it."

The words settled heavily between them.

Before Zoey could respond, he had already walked past her, heading toward their parents’ bedroom.

"Mother is sleeping—"

"Never try to investigate her," Zachary cut in without even looking back. "This is my only warning, Zoey. Don’t test my patience."

He opened the door and went inside.

Zoey remained where she was, her eyes fixed on the closed door long after he disappeared behind it.

She was furious.

Yet beneath that anger, something else began to grow. Curiosity.

From Zachary’s reaction alone, she could tell Sienna was no ordinary woman.

After a few minutes, Zoey let out a quiet, humorless laugh.

"Wow, Zach... you really went all out for her, huh?"

She tilted her head slightly, eyes narrowing as she stared at the door.

"Sienna," she murmured. "Whoever you are... I hope you truly have what it takes to stand beside my brother, and to be worthy of his attention."

Her lips curled into a faint smile.

"Otherwise, this family will eat you alive."

Finally, she turned and walked away, her heels clicking softly against the floor as she headed back toward the living room.

She glanced around, expecting to see Skylar still on the sofa, but it was empty.

"Where is he? Did he go upstairs to rest?" she muttered, frowning slightly.

A flicker of regret crossed her face.

She had planned to ask for Sienna’s full name.

But that chance was gone. For now.