Getting on her knees, Emma dusted off the bunker door until she found what she was looking for: a hole to match her key. But the hole was packed tightly with three decades’ worth of dirt. And no matter how much Emma scraped at it, she could not clear the dirt away.

Chirrup. Emma looked up from the dirt-filled keyhole to see SkD staring back at her. Its screen blinked.

I said to Emma, “SkD would like to make wind.”

Emma giggled.

I stared at her, confused. “What is so funny about SkD making wind?”

“Nothing,” she said, still giggling. “Go for it, SkD! I officially give you permission to make wind.”

The small robot extended one of its arms toward the keyhole. From the tip of its finger came a burst of highly pressurized air. FWOOSH! A tiny storm aimed straight into the keyhole. Dirt flew everywhere. When the robot was done, the hole was clear.

Emma grinned at SkD. “Thanks! You’re awesome at making wind!”

She took a deep breath. Inserted the key. Turned it. And then—

Click.

The sound came from deep within the hatch.

Emma grabbed the handle. A thick metal cylinder. She pulled/pulled/pulled.

Nothing happened.

“Perhaps I can be of assistance.” Ceeron took hold of the handle. With a single tug, the massive robot twisted the cylinder 90 degrees.

And when it lifted, the door eased open.

Curiosity surged through my operating system. I leaned forward. So did the others. All four of us peered down the opening. This is what we saw:

A round metal tube.

Stretching down/down/down.

Into the shadows.

Into the bunker.

A ladder was attached to one wall of the tube. Emma eased herself onto it, one foot at a time. She climbed down the ladder. When she was halfway into the tube, she hesitated. Her eyes turned in our direction.

She said nothing, but her silence said everything. It was full of fear/hope/excitement/dread.

“Good luck,” I said.

SkD beeped with agreement. Its screen glowed its own version of support.

Ceeron spoke in a rumbling voice. “We will see you again later, alligator.”

This brought a smile to Emma’s face. “After a while, crocodile.”

And with these strange words, she set into motion again. Down/Down/Down.

Deeper underground.

Until the shadows swallowed her whole.

01100100

While we waited, I counted in binary.

When I reached a million, I started over.

Again.

And again.

My brain filled with a steady stream of ones and zeroes. It was the only way to keep my thoughts from wandering down the dark pathways of probability.

Probability[1]: The humans inside the bunker do not possess the medicine Emma needs.

Probability[2]: They will refuse to share it with her.

Probability[3]: They died long ago.

Probability[4]: . . .

I did not want to think about these scenarios, and so I repeated my task, concentrating on ones and zeroes, stacking them up in neat/orderly rows until—

A sound from far below.