I looked to the left. “Bathroom!” I said to Jess. She had Jack in a piggyback, and she raced toward it as I hobbled after. I shut the door behind us in the small powder room. I had to wedge myself next to the toilet to find space.

“Rocky! Oh no!” I said as I heard his bark. “We have to let him in.” I reached for the door just as it shook with another blow from Darlene. The door split up the center, since it was made from cheap foam core.

Rocky’s barking grew louder as he got closer to the bathroom.

“Rocky, go! No!” I said. The thudding against the door stopped, and a scraping sound replaced it, like a whirring. Then, an acceleration.

The awful sound of Rocky’s whimper filled the bathroom. I didn’t hesitate to wrench open the door to save him. He was backed into the corner by the front door, huddled, his front two paws bleeding where Darlene had run them over. And she was reversing again, ready to strike.

I charged after her, and she slowly spun around, the small rotating brush in the back moving like a cockroach’s antenna. She paused, and then spun excitedly as she prepared to accelerate toward me.

“Keep Jack,” I called to Jess in the bathroom. I steeled myself as she came toward me.

“Kill it!” Jess screamed.

I tried to calculate the distance to the bathroom door and whether we could escape out the window into the yard. Surely she couldn’t break down the front or back door. Then we could run inside and grab Emily, we could call Mark from Jess’s house, and he could come home and kill it, although I didn’t want to think about his reaction when we told him my vacuum had turned homicidal.

During my hesitant calculations, Jess activated. She hip-checked me as she hurried past, leaping over the laundry basket at the entrance to the basement. She ran toward Darlene like an Olympic sprinter, skidded to a stop on the floor, and brought her heel down as hard as she could on it. Over and over. Until there was nothing left, except a few whirs and beeps.

Finally, Darlene emitted a womp womp sound, the same as when she got stuck at the top of the stairs or ran out of power.

And then her light went out.

Red-faced, Jess looked up at me and wiped her forehead with an arm before putting her hands on her hips.

“Well, that was really fucking weird,” she said. “Okay, I believe you, Amy.”

I heard a gasp from behind her, and Emily stepped aside, looked from the now-dead Darlene to me, and said, eyes wide, “It was her.”

Fear flooded my veins as I crouched down in front of her, reaching for her hands. “Who, honey?” My voice cracked.