Chapter 1

When I went for my grad school physical examination, everyone else breezed through it.

But my report had a glaring red stamp on it.

My blood arsenic level was 0.87 mg/L, four times higher than the safe limit.

The doctor took off his glasses and checked the report over and over. "Melanie, have you been exposed to arsenic for a long time? Like pesticides, industrial chemicals, or maybe medicine?"

I was stunned for a solid ten seconds.

All I could picture was one thing. The old black pot that had been in the kitchen for twenty-three years and the herbal tonic my mom brought to me every single day.

"Mel, drink it hot. A cold drink is bad for your stomach," she'd say.

She must've said that thousands of times since I was little.

Everyone in Willow Creek said Linda Foster was the most devoted mom in town.

For twenty-three years, she never missed a single day making herbal tonic for her sickly eldest daughter.

I gripped the report, my fingers went numb.

No way. That couldn't be true. There must be some misunderstanding.

I folded the report into thirds and slipped it into the inside pocket of my down jacket.

My fingers were still shaking as they brushed the edge of the paper.

My advisor gave me three days off.

I bought a ticket for the next train back to Willow Creek.

I spent the whole two and a half hours staring out the window.

The plains in October were already turning yellow.

It was almost dark by the time I arrived at the station.

The alley back home looked the same as I remembered. Brick walls, old power poles, and cracks running through the concrete road.

Before I reached the door, that familiar smell hit me.

It was bitter and astringent, with a faint burnt edge.

After twenty-three years, that smell had been burned into my bones.

I pushed open the gate. The kitchen light was on.

Mom was crouched by the gas stove, stirring with a long wooden spoon.

The black pot was bubbling away.

"Mel, you're back?" She didn't look up. "Perfect timing, the tonic's almost ready. I bet you haven't been taking it properly at school."

I watched her toss in a final handful of herbs.

She moved so fast that I couldn't tell what it was. "Mom, what was that?"

"Dandelion root." She turned the flame down low. "You've always been weak since you were a kid. Dandelion root can strengthen your body."

I didn't ask any more questions.

I sat down at the table, waiting for her to bring the tonic over.

Ten minutes later, she strained the tonic into a porcelain cup.

The brown liquid steamed, with a thin layer of fine residue settled at the bottom.

"Drink it while it's hot," she said.

I picked up the cup. As I brought it to my lips, I caught a faint whiff of garlic.

I'd never noticed it before. Or maybe I never knew what I should be noticing. But now, that number from the report was stuck in my head like a nail. [Blood arsenic level: 0.87 mg/L.]

Arsenic is colorless and odorless. But when it oxidizes, it gives off a faint garlic smell.

I set the cup down. "Mom, I already had dinner at school. I'm pretty full. I'll drink it later."

Her hand froze for a split second.

Just for a moment. Then she smiled. "Alright, leave it there. But don't forget. If it gets cold, I'll heat it for you."

I went back to my little room.

Once the door was closed, I crouched down on the floor and hugged my knees.

My mind was a mess. 'No way. How could this be? She is my mom. She's been scrubbing that pot for twenty-three years. She's been picking out those herbs for twenty-three years.'

I took three deep breaths and stood up.

I went to the living room and poured myself a glass of water.

On my way past the kitchen, I dumped most of the tonic from the cup.

The rest, liquid and dregs, I poured into the sealed sample tube I'd brought with me.

There were about 3 fl oz. That was enough.

Back in my room, I wrapped the sample tube in some clothes, hid it at the very bottom of my suitcase, and then I took the empty cup back out. "Mom, I finished it."

Linda took the cup and glanced at the bottom. "Good girl."

She smiled as gently as she had every single time for the past twenty-three years.

I went back to my room and locked the door.

My palms were slick with sweat.

My little brother, Michael Foster, texted me. [Mel, you're home?]

I typed out three words, and then deleted them.

In the end, I replied with a single "Yeah."

He didn't text anything else.