My husband inserted the tiny memory card into his laptop.

The screen flickered.

For a moment, nothing happened.

Then the grainy footage from my parents' front porch appeared.

The timestamp showed three days before I found them.

My mother was watering her flowers.

My father sat in his favorite chair reading the newspaper.

Everything looked normal.

Then a familiar car pulled into the driveway.

My stomach tightened.

The driver stepped out.

My younger sister, Rachel.

"What?" I whispered.

My husband looked just as confused.

Rachel smiled as she approached the front door carrying a basket.

My parents welcomed her inside.

The footage continued.

An hour later, Rachel emerged alone.

She glanced over both shoulders.

Then she did something strange.

She removed a small bottle from her purse and threw it into the trash bin beside the garage.

The video ended.

I felt sick.

"No..."

My husband immediately drove back to my parents' house.

The trash had already been collected.

But luck was on our side.

The outdoor security system had captured another angle.

This time the image clearly showed the label on the bottle.

A toxic chemical.

One that matched the substance found in my parents' blood.

I stared at the screen in disbelief.

Rachel wasn't just my sister.

She was my best friend.

Or so I thought.

The police were contacted immediately.

But the deeper they investigated, the darker the truth became.

Because Rachel hadn't acted alone.