Don’t look. Don’t look. Just keep going.

Sarah took her sense of sight out of the equation, instead focusing everything on her ears, attuned to all the far-off creaks and gurgles that the building made around her as she crept down the last few steps to the ground level. It was hard to tell the sounds from their echoes, reverberations that described immensity, emptiness, size, vacuity.

Another step. And one more.

Now she aimed the Express downward, allowing herself to look again. No blood this far down, no soft, broken shapes, the floor clean.

She pushed the door open to the ground floor. This was how they’d come down before from their entrance on the first floor, but everything was different now, distances stretched, swimming in near blackness.

“Mommy, can I look now?”

Sarah nodded, was about to say, Go ahead, you won’t see much, when she heard the speaker crackling up somewhere in front of them.

She froze, the boy clutching her shoulder.

“What’s that, Mommy?”

“A radio, sounds like.” The noise she heard was primarily composed of static, with an occasional chirp or flutter of electronic feedback. It sounded far away, she thought, but then didn’t everything sound far away in the darkness?

There was another muted cloud of static, and Sarah heard a voice crackling through the speaker, saying, “Unit Six, do you copy?”

Sarah squinted ahead, holding the toy engine slightly higher as she made dubious progress. The arm she was using to carry Eli had long ago stopped aching and was now numb and trembling with fatigue, but she couldn’t quite bring herself to put him down. Not with the darkness so close, rubbing up against them like a thick fog.

“Unit Six?” the radio voice said. “Confirm position.”

Up ahead on the left Sarah could make out the outline of a door. She raised the Express. No sign here. She put her hand on the knob, prepping for it to be locked. But it turned easily in her hand.

“Mommy?” Eli whispered. “Can I hold my train for a little?”

She realized the comfort that she’d been denying him, clutching his toy for as long as she had; yet she was surprised at how difficult it was to relinquish. “Here, hold it up so we can see inside,” she whispered back, and without another word Eli took the Express, let go of her neck, and slipped down to stand on his own. As much as she didn’t want to let him go, her right arm sighed with relief. “You have to stay right next to me, understand? Do not let go of my hand.”

“Okay.”

She nudged the door open just a few inches, cocking her head to listen. She didn’t have to wait long.

The radio sounds were appreciably louder on the other side of the door, a good sign, maybe. “Hello?” Realizing no one could hear her unless she at least risked speaking in normal room volume, she spoke louder. “Is someone here?”