She hit the ground next to the lumbering Amos and hopped again, beating them both to the airlock door. She tapped the button and the outer door cycled open. Of course. Who locks their door on Io? No one is going to hike across a wasteland of molten silicon and sulfur to steal the family silver.

Amos plowed past her into the airlock, stopping for breath only once he was inside. Bobbie followed Prax in a second later, and she was about to tell Amos to cycle the airlock when her radio died.

She spun around, looking out across the surface of the moon for movement. Amos came up behind her and put his helmet against her back armor. When he yelled, it was barely audible. “What is it?”

Instead of yelling back, she stepped outside the airlock and pointed to Amos, then pointed at the inner door. She mimed a person walking with her fingers. Amos nodded at her with one hand, then moved back into the airlock and shut the outer door.

Whatever happened inside, it was up to Amos and Prax now. She wished them well.

She spotted the movement before her suit did. Something shifting against the sulfurous yellow background. Something not quite the same color. She tracked it with her eyes and had the suit hit it with a targeting laser. She wouldn’t lose track of it now. It might gobble radio waves, but the fact that she could see it meant that light bounced off it just fine.

It moved again. Not quickly, and staying close to the ground. If she hadn’t been looking right at it, she’d have missed the motion entirely. Being sneaky. Which probably meant it didn’t know she’d spotted it. Her suit’s laser range finder marked it as just over three hundred meters away. According to her theory, once it realized it had been spotted, it would charge her, moving in a straight line to try to grab and rip. If it couldn’t reach her quickly, it would try to throw things at her. And all she needed to do was hurt it until its program failed and it self-destructed. Lots of theories.

Time to test them out.

She aimed her gun at it. The suit helped her correct for deflection based on the range, but she was using ultrahigh velocity rounds on a moon with fractional gravity. Bullet drop at three hundred meters would be trivial. Even though there was no way the creature could see it through her helmet’s darkened visor, she blew it a kiss. “I’m back, sweetie. Come say hi to momma.”

She tapped the trigger on her gun. Fifty rounds streaked downrange, crossing the distance from her gun to the creature in less than a third of a second. All fifty slammed into it, shedding very little of their kinetic energy as they passed through. Just enough to burst the tip of each round open and ignite the self-oxidizing flammable gel they carried. Fifty trails of short-lived but very intense flame burned through the monster.

Some of the black filament bursting from the exit wounds actually caught fire, disappearing with a flash.

The monster launched itself toward Bobbie at a dead run that should have been impossible in low gravity. Each push of its limbs should have launched it high into the air. It stuck to the silicate surface of Io as though it were wearing magnetic boots on a metal deck. Its speed was breathtaking. Its blue eyes blazed like lightning. The long, improbable hands reached out for her, clenching and grasping at nothing as it ran. It was all just like in her dreams. And for a split second, Bobbie just wanted to stand perfectly still and let the scene play out to the conclusion she’d never gotten to see. Another part of her mind expected her to wake up, soaking with sweat, as she had so many times before.

Bobbie watched as it ran toward her, and noted with pleasure the burnt black injuries the incendiary bullets had cut through its body. No sprays of black filament and then the wounds closing like water. Not this time. She’d hurt it, and she wanted to go on hurting it.

She turned away and took off in a bounding run at a ninety-degree angle to its path. Her suit kept the targeting laser locked on to the monster, so she could track its location even without turning around to look. As she’d suspected, it turned to follow her, but it lost ground. “Fast on the straightaways,” Bobbie said to it. “But you corner like shit.”

When the creature realized she wasn’t going to just stand still and let it get close to her, it stopped. Bobbie stumbled to a stop, turning to watch it. It reached down and tore up a big chunk of ancient lava bed, then reached down to grip the ground with its other hand.

“Here it comes,” Bobbie said to herself.

She threw herself to the side as the creature’s arm whipped forward. The rock missed her by centimeters as she hurtled sideways. She hit the moon’s surface and skidded, already returning fire. This time she fired for several seconds, sending hundreds of rounds into and through the creature.

“Anything you can do I can do better,” she sang under her breath. “I can do anything better than you.” The bullets tore great flaming chunks out of the monster and nearly severed its left arm. The creature spun around and collapsed. Bobbie bounced back to her feet, ready to run again if the monster got back up. It didn’t. Instead, it rolled over onto its back and shook. Its head began to swell, and the blue eyes flashed even brighter. Bobbie could see things moving beneath the surface of its chitinous black skin.

“Boom, motherfucker!” she yelled at it, waiting for the bomb to go off.

Instead, it bounced suddenly to its feet, tore a portion of its own abdomen off, and threw it at her. By the time Bobbie realized what had just happened, the bomb was only a few meters from her. It detonated and blew her off her feet. She went skidding across Io’s surface, her armor blaring warnings at her. When she finally came to a stop, her HUD was flashing a Christmas display of red and green lights. She tried to move her limbs, but they were as heavy as stone. The suit’s motion control processor, the computer that interpreted her body’s movements and turned them into commands for the suit’s actuators, had failed. The suit was trying to reboot it while simultaneously trying to reroute and run the program in a different location. A flashing amber message on the HUD said PLEASE STAND BY.

Bobbie couldn’t turn her head yet, so when the monster leaned down over her, it took her completely by surprise. She stifled a scream. It wouldn’t have mattered. The sulfur atmosphere on Io was far too thin for sound waves to travel in. The monster couldn’t have heard her. But while the new Bobbie was at peace with the idea of dying in battle, enough of the old Bobbie remained that she was not going to go out screaming like a baby.

It leaned down to look at her; its overlarge and curiously childlike eyes glowed bright blue. The damage her gun had done seemed extensive, but the creature appeared not to notice. It poked at her chest armor with one long finger, then convulsed and vomited a thick spray of brown goo all over her.