Somehow my red line following got fouled up, and I arrived again at the big aquarium, where I stood staring at the oversized angelfish that decided to stare back at me. Something that Sarah had told me was called a black ghost slithered his eel body through my peripheral vision. I imagined that if I chose to hallucinate at that moment, the angelfish would speak to me, say something cryptic and profound; as I stood there entertaining this weird notion, it dawned on me that I was essentially hallucinating anyway. I looked down, rediscovered the red line, and set off again with neither more nor less resolve. This time I found Dr. Gurewich’s office and my family.

Sarah embraced me as if she had not seen me in a very long while. It surprised me, scared me somewhat, though I loved the feeling of it, being reminded of when she was so much my baby. She had never felt smaller.

Dr. Gurewich called in a nurse. “Melissa, would you take Sarah and get her blood pressure, respiration, and heart rate?”

It was so clear that she was simply removing Sarah from the room that I became immediately terrified. Meg saw it in my eyes, and I saw it in hers.

“We’ll be right here, baby,” Meg said to Sarah.

The nurse led her away and closed the door.

Gurewich’s eyes looked tired. She rubbed her forehead and temples and appeared to be not all there.

“Were you up late?” I asked her.

She absently reached into her knitting basket and pulled a skein of blue yarn onto her desk. “No,” she said. She paused and kneaded the yarn with her hand. “Sometimes I get migraines.”

I nodded. “What have you learned?”

“That scents often bring them on,” she said.

“About Sarah,” I said.

“Of course.” The doctor collected herself.

“What is it?” Meg asked.

“I first became suspicious when Sarah’s urine tests showed dolichol. So we took a closer look and did find vacuolated lymphocytes. Those are white blood cells that have holes in them.”

“Okay,” I said.

“There is a group of disorders called neural ceroid lipofuscinoses. NCL.”

“Okay.”

“I believe—I strongly believe—that Sarah has Batten disease. That would explain all of her symptoms. Her skin and tissue samples support this diagnosis.” Gurewich kneaded her yarn.

“How do we treat it?” I asked.

Meg was silent.

“We can’t,” Gurewich said.

“You mean she’ll just live with it, have these seizures? Can we control the seizures?” I asked.

Gurewich leaned even more forward. “There is nothing we can do.”

“Excuse me?” I said.

“What are you talking about?” Meg asked. “What are you saying?” She stood up and sat right back down.

I took Meg’s hand.

“The DNA analysis shows a mutation in the CLN3 gene on chromosome sixteen.”

“Are you saying that one of us gave our child this?” Meg said.