It was an incoming call from an unknown Brooklyn number.

I hesitated, my finger hovering over the green answer button.

The lobby buzzer began to ring, a long, continuous whine that filled the apartment.

At the exact same moment, the phone in my hand vibrated with a second alert.

It was a notification from our shared security system.

The motion sensor in the boiler room had just been triggered.

Someone was down there with Carl.

I let the phone ring out.

The buzzer in the lobby stopped its long whine, leaving only the sound of my own quick breathing.

I stared at the security app on my screen, the red dot flashing over the basement blueprint.

I did not call Jake back.

Instead, I slipped my key ring into my pocket and pulled my wool cardigan tight around my shoulders.

The hallway outside my door was drafty and smelled of boiled cabbage from 2B.

I walked softly, keeping my back close to the painted brick wall.

The yellow bulbs overhead flickered, casting long, trembling shadows down the corridor.

As I passed Mrs. Patterson’s door, I heard her television murmuring inside.