“I’m not waiting.” Eva sent the distress signal, returned the device to her satchel, and peered back around the tree trunk. A thin ribbon of smoke drifted up from the exhaust vent into the night sky. In it were the burnt, atomized remnants of her Sanctuary. Perhaps even of Muthr.

“Stupid robot.” Eva wiped her eyes with the back of her sleeve. “I knew we should have explored the surface sooner.”

Another large tremor rippled up from the shaft, followed by the emergence of a dark, burly figure from another opening in the ground, farther in the distance. “The main entryway,” Eva whispered, remembering the floor plan that the Omnipod had showed her.

The large, shadowy figure remained still at the entryway as it surveyed the forest. Eva couldn’t make out many details from her vantage point, but whatever this intruder was, it was big and had many legs and arms. It lifted its large head and snorted loudly, then abruptly stopped. Turning, the intruder raised a long rodlike apparatus right in Eva’s direction. She could hear a distinct electronic hum rising in pitch, followed by a woom sound of intense sonic vibration. The tree trunk Eva was hiding behind exploded, throwing her backward.

The concentrated sound wave had blasted a hole, the size of Muthr, through the thick trunk. Digging herself out of the debris that had dropped down onto her, Eva heard the groan of the weakened trunk as the tree began to topple. She scrambled out of the way, and the sprawling treetop crashed into the ground behind her, sending leaves and branches flying in all directions.

She got up and took off, running through the dense woods. Soon Eva could hear only her footsteps padding across the soft forest floor.

Is he gone? Did I outrun him? she thought.

Just to the right of her another tree was reduced to splinters by a sonic explosion. She was being followed.

She ran for some time, zigzagging through the undergrowth. Her lungs burned from the crisp, chilly night air. As she dashed around the enormous trunk of a tree, Eva tried to locate her attacker. She leaned against a low branch and caught her breath, wondering where she was.

Eva looked up through the wide leaves above her. In the shadowy forest there wasn’t enough moonlight for her to take in her surroundings and find a safe place to hide.

Perhaps if I get to a higher vantage point, I can see more. She grabbed on to the branch. Like she had done many times on the monkey bars in the Sanctuary’s gymnasium, Eva lifted herself onto the branch and tested her weight on the platform of hardened leaves: They held her.

Eva hopped from leafy platform to platform. In moments she found herself on the moonlit top of the irregular tree. Peering over the edge of the topmost bough, Eva could see the swift-moving tapered shape of her assailant below.