Sonic Crab

*First appeared in writing.com for an SF flash fiction competition, but the moderator never called a winner, in fact, the forum just disappeared. So this could be the winning entrant.
Victor heard the sonic-crab.

The short bursts of ultra-bass tones echoed across the night-bound, dead quiet city. He suspected the auton may have already detected his presence when he entered the supermall district. No matter how discreetly he travelled, these autons were sound sensitive. As well as emitting audio, these things detected it.

Listening.

One beep on the horn would hush them all to silence.

Victor stopped the F-550 at every desolate street corner, listening to the dark city for clues for the demonic sound's direction. He drove in a wide circle trying to pinpoint its epicenter. Like cicadas, these things haunted him for the past few nights. They seemed to be spread throughout the uninhabited metropolis, their true purpose unknown, their function a new mystery.

Capturing one would be helpful, but deadly.

Fear was not an option. Victor lost all remnants of it years ago. He had nothing to live for. He managed to save his family from the robocaust, but during the aftermath, fate, deathtoasters, and flying blenders took them away from him. Though Victor methodically patrolled the rendezvous points, especially the supermall district, his pragmatic spirit had given up on finding his son ever again. Staying alive or finding another living human was a futile exercise now. Even if he did find someone, it would mean nothing, achieve nothing; the thrashing that self-design technology gave to humanity had been a decisive, binding blow. Victor feared not for his safety, for he sought the nuclear option. Mutual obliteration. He intended to inflict the same destruction upon System One and did not plan to stop till he himself was resoundingly dead.

The sky brightened, no longer a deep black. The shadows of the city skyline emerged from the vast nothingness. Passing an intersection he spotted the six-legged metal critter, hiding among a pile of debris just beyond the railway overpass. He eased off the accelerator allowing the F-550 to slow down to a halt.

It's not that big, he thought, having imagined a monster. Its legs were retracted but the cone-shaped dish above its white semi-circular body protruded vertically. Sitting motionless on the curb it looked like a twentieth-century hi-fi stereo on roids was about to cross the road. Victor could not discern what it was designed to do. The thing gave out energetic bursts of sound waves at either super low or ultra-high frequencies.

Why? Who the fuck knew.

Seeing that sonic-crab possessed no obvious weaponry, Victor hit the accelerator. The F-550 leapt forward and hurtled down the street. The sonic-crab remained still. Victor aligned the bull-bar and dropped a gear. As soon as the F-550 mounted the footpath the robot's legs sprouted and sprang outward, the dish folded down and the unit launched into the air. The F-550 hit the pile of rubbish, swerving in time to match the trajectory of the sonic-crab.

Let's see how fast this thing is.

Victor changed gears while white-knuckling the steering wheel. The sonic-crab, bouncing sideways, abandoned the hard surface of the road seeking rougher terrain. Its six legs seemed more accustomed to it. Victor did likewise, his eagerness to down run this malcreation undeterred. They machine sprinted up a hill and headed for the railway tracks. Victor took a shortcut through a backyard, smashing up fences till the F-550 ascended the grassy slope. He did not bother looking about for any oncoming trains, there were none and would never be any. The railway sleepers on the track rocked the F-550 about but failed to hinder his speed. The sonic-crab could run fast, but it was no match for the three hundred horse-powered F-550.

That was the System One's weakness. Battery power. Sure, the capacities of batteries were impressive, even pre-doomsday ones, but these ever-evolving killer autons were drawing more and more amps. This sonic-crab had spent all night bellowing out low-frequency tones at a hundred decibels. It would be due for a recharge. When the petroleum guzzling F-550 began gaining on the sonic-crab, Victor throttled it some more. He didn't want to damage it; he planned to smash it into little pieces. The sonic-crab slowed, then suddenly stopped and turned. Its feet dug in and the disk flipped open.

BWEOOOORRRV!

The sound pressure wave smacked his ears,

The bull-bar collected the robot, ending the horrid, deafening roar. Victor swerved to the side as smashed robot bits were flung everywhere. The F-550 skidded to a stop. Victor jumped out to inspect the mess. Squatting, he turned over what was left of the chassis. Lots of wires. Heavy magnets. Big servos. What he wanted was the identity tag.

He found it inside the battery shell.

SYS10.M230994.T0002.S:RrOrrRgzJ

System 10.

"I knew it," he said. Another new factory had come online. He suspected it a long while but now, faced with confirmation, Victor had one more abominable killbot facility to add to his takedown list. If only he knew where any of them were located.

The dawn sky presented him with another more profound horror. Deep into solar-power territory, where System One used each domestic solar panelled roof to fuel its presence here, Victor only had around five hours before a horde of autrons were charged up enough to recommence their hunt and destroy directive.

Then he heard it.

The echo pounded the sky above.

"Victoooor." A grumbling, demonic voice.

It came from all direction.

Laughter. Multiple sources.

Other sonic-crabs.

“Dad?”

Victor recognised his son’s voice.

A trick.

Dismissive, Victor climbed back into the F-550 and sped away, headed south, towards the relative safety of the inner suburbs. He could hack away at the energy grid all day and night, but System One always found a way to get electricity to its minions. Down south, where older, poorer neighbourhoods neglected to upgrade to solar, he managed to destroy enough of the grid to knock out a thirty block radius.

For now, it was the safest part of town to live in.

For now.