Amy felt a clammy shiver, far deeper than the cold of her rain-soaked hoodie, creep down her arms. “You know about Rover,” she said.

“We called it that, too!” said Nurse Becca, a little too loud and with a horrible laugh behind it. “Just came to me. Felt right. Then, when things started to get bad, I did some digging … and they all call it that, everyone it chooses. It likes that name, for whatever reason. Who’s it bonded with?”

“I don’t know what you—”

“No, no, listen,” said Nurse Becca, looking at Amy. Her car drifted into the other lane; she swerved and winced at the honk of the oncoming driver as they passed. “Let’s just stop pretending everything’s normal, okay? I know it all. So: It bonds with someone. A favorite, the one it can talk to, whose mind it sees. Who is it?”

Amy felt her mouth go dry. “My little sister, Katie. Who’d it bond with at the shelter?”

“Me,” said Nurse Becca in a sad voice. She gulped, glanced at Amy, then tightened her hands on the wheel with a creak of leather. “I knew its name. I could hear it, almost like it was speaking in my head. At first, it was really nice, finally having a companion, a dog of my own. Until it got jealous. If I left it for a moment, or if anyone else would reprimand it, it would … do things. Our devices would all go on and off. People had these awful nightmares. The other animals got sick, or had really bizarre accidents, or attacked each other. Then it started making accidents happen to people.” She blinked hard. “It was when Frank tried to have a talk with me about it that things went really wrong. It could hear what Frank was saying, through my mind. So it threw him, somehow, down some stairs. It looked like an accident. And how would that sound to the cops? The dog did it.” She laughed again, even more horribly this time.

Amy’s eyes glazed over as she replayed the sight of Fieldston Kade’s bleeding body on their front lawn. “It threw a man through our front window,” she said.

Nurse Becca was silent a second, then said, “It’s getting stronger. You have to be careful.”

“Where did it come from?” asked Amy.

“An old woman donated it to us,” said Becca. “She brought it in drugged. We thought that was cruel, but she had the right idea. I think she saw it long before any of us did.”

“How’d you get rid of it?” asked Amy.