The Billionaire's Heir I Never Knew Was Mine

The quiet hum of the engine wrapped around the car like a soft, steady lullaby, but it did nothing to calm the storm building inside Zachary’s mind.

"Mr. Handsome Zach... If I really lose my job..."

Her voice sounds soft, fragile, and slightly slurred, echoed again in his memory, as if it had settled there without permission.

It didn’t sound like the composed woman he had just shared dinner with.

It didn’t sound like the confident manager who handled guests with calm ease.

It sounded... vulnerable.

Zachary’s grip around his phone tightened slightly, his knuckles turning pale as his gaze drifted toward the tall apartment building standing quietly outside his car window.

Lights flickered behind a few windows, ordinary and peaceful, yet somehow, he felt uneasy.

He could sense her sadness through that brief moment. It wasn’t loud or dramatic. It was subtle, almost hidden between her playful tone and drunken laughter. But it was there.

And for some reason, that bothered him more than it should.

"...can I work for you instead?"

Her words could be heard again, softer this time, followed by silence.

A long, unsettling silence.

"Sienna?" he called her, his voice lower, more serious. "Are you still there?"

Nothing.

Not even the sound of her breathing.

And then the call ended.

Zachary lowered his phone slowly, staring at the dark screen as if expecting it to come back to life on its own.

’She hung up?’ he muttered under his breath.

His eyes lifted once more toward her apartment building.

’Is she alright?’

The question came without warning, slipping into his thoughts before he could stop it.

’Why did she suddenly get drunk...from all the people she knew, why did she call me?’

The car remained still, parked quietly along the side of the road. The city lights reflected faintly on the glass window, casting soft shadows across his face.

For a moment, he considered getting out.

Just walking into her apartment.

Just making sure she was fine.

Just as he was about to make a decision, suddenly—

"Sir, should we go into the apartment complex, or do you want to go back home?"

The driver’s voice broke through his thoughts like a stone hitting still water.

Zachary is slowly returning to the present. His expression hardened slightly, the brief hesitation disappearing as quickly as it came.

"Go back home," he ordered calmly.

The car engine responded almost immediately, the vehicle pulling away from the curb with smooth precision.

Zachary leaned back against the seat, placing his phone aside as if it had suddenly become heavier than before.

Then, he picked up the iPad resting on his lap. The screen lit up, revealing a detailed report.

Sienna Adams.

Her name stood there clearly, neatly typed, simple... yet now it carried a weight he hadn’t expected.

He scrolled through the document slowly, his sharp eyes scanning each line with focus. Her basic information, her toxic family, her education, her career path, everything appeared normal, even impressive.

Front Office Manager at Imperial Hotel.

Efficient. Professional. No major issues recorded.

Yet his finger paused mid-scroll when he saw a gap. A missing piece from seven years ago that remained unexplained.

Zachary’s gaze darkened slightly, interest sharpening like a blade finding its edge.

He hadn’t planned to look into her this deeply.

At first, it had only been curiosity... simple, harmless curiosity about a woman who spoke to him without hesitation, without calculation.

But now...

It was something else.

A faint smile slowly appeared on his lips as he leaned back, eyes still fixed on the screen.

"Sienna..." he murmured softly, almost thoughtfully, his thumb brushing lightly over her name on the display. "How could it be you?"

There was recognition buried deep within him. Something familiar that refused to fully surface, like a memory just out of reach.

And that unsettled him.

After a while, he placed the iPad aside and picked up his phone again, his movements calm but decisive.

His fingers moved quickly across the screen.

"Conduct a full investigation into Sienna Adams. What exactly happened seven years ago?"

He didn’t hesitate before pressing send.

Almost immediately, a reply came in.

"Yes, sir. The report will be in your email soon."

Zachary stared at the message for a few seconds, his expression unreadable.

The car continued moving through the quiet streets, city lights passing by like fleeting thoughts.

He leaned his head back slightly, closing his eyes for just a moment.

But rest didn’t come.

Instead, her voice returned.

Her laughter.

Her strange, cheerful tone as she called him "Mr. Handsome Zach. Mr. Dangerous-for-my-sanity..."

And that ridiculous, unexpected question, "Can I work for you instead?"

A soft chuckle escaped his lips before he could stop it.

"Did she even realize what she said?" he muttered quietly, shaking his head slightly.

For a brief moment, he imagined it. Her sober face. Her calm, composed expression suddenly cracked with embarrassment when she remembered this call.

That image alone was enough to make his amusement linger.

Zachary opened his eyes again, his gaze settling on the road ahead.

For someone like him, people usually approach with intention. With calculation. With desire.

But Sienna, she stumbled into his life twice. Unplanned. Unfiltered.

And now, even drunk, she spoke to him over the phone with such fearlessness... without knowing who he really was.

That alone made her dangerous.

Dangerous enough that she stays in his thoughts longer than he usually allows. Longer than any woman, for that matter.

Zachary exhaled slowly, his expression returning to its usual calm, controlled state.

"This is interesting..." he murmured under his breath.

The night stretched on quietly outside the window, and his thoughts refused to settle.

...

The next morning arrived far too quickly, as if the sun had decided to take revenge on Sienna for her poor decisions the night before.

A faint groan slipped from her lips as she shifted slightly, her entire body protesting the movement.

Her neck felt stiff, her back sore, and her head...well, her head felt like it had been used as a drum in a very enthusiastic percussion concert.

Slowly, with great effort, she forced her eyes open.

The ceiling greeted her first.

"...Why is my ceiling so close?" she muttered weakly, her voice dry and hoarse.

Blinking a few times, her blurry vision gradually cleared, and reality hit her like a delayed slap.

She was on the sofa.

Still in her work clothes.