Gemma rippled her fingers just to watch them behave. Then again, tumbling a coin along the knuckles. Tight coordination, actually happening with her fingers! This should not be, and yet here she was outside, and she had control of her fingers. And her legs. She could run. Fast. This wasn’t a dream.

She ripped open a wrapper and chomped through a couple of energy bars. Only after tapping the XO wrist control to set her muscles on low energy/endurance did she regret eating her emergency rations so early; so carried away with the effortless, fine-grained motor control. The joy of just doing stuff; that, at least, had not faded.

The food would now sit in her gut while her body cooled down, which always meant trapped wind. Not good on a stakeout lasting hours.


Parkinsons had struck out of nowhere in her early teens. Rapidly, inexorably, wheelchair-bound, totally dependent on others 24x7. Gemma’s mother, a technician working in a university research lab, switched to a related one studying muscle control. She brought her work home and worked with and on Gemma.

To intercept the tremor-inducing nerve signals in the brain was not, yet, practical. It was too error prone and, anyway, far too expensive. By tapping into the main muscle groups they could intercept each twitch and steer it to a useful movement, or counteract it completely. Initially, research focused on managing muscle spasms, with electrical contacts at each main muscle junction working out from the spine, all the way out to each individual finger and toe. Whereas fine-grained control would have been not achievable via the nerve groups coming out of the brain and the spine, by taking the control out to the peripheral motor regions and overriding at the muscle, the tech was actually very simple and reliable; little more than electrode-pads held in place by elasticated straps over each of the main muscle junctions, linked to a central, battery-powered processor; now powerful enough to handle the intense signal processing.

Dad had given up his job to stay at home and look after Gemma, and this had been the way of things for what should have been her secondary school years. Then Gemma stood up, unaided by anything except the straps and the wires hooked into a box dangling from her neck. Dad was no longer needed at home. That was awkward, but he took it well.

Gemma and Tech Mum (nicknames stick) developed a self-assembly process that allowed Gemma to start naked and fully vulnerable to all that the Parkinsons was (and still is - not cured in any way) doing to her, and yet be able to don the full exoskeleton piece by piece under her increasing control. It packed down into a briefcase-sized container, with the outline of a hand on one side, next to a hole. Press her hand against that patch and blessed control would start to happen. First the fingers, then the thumb, and she could push her arm in and don the wrist control. With one hand controlled, she rigs up the other, and then the major limbs and spine. The final two main electrode patches attached to a pair of pants holding them in place, and she was no longer incontinent. The whole process of dressing into the XO was, with practice, achievable solo in just under an hour.

With some care, and basically play-acting, Gemma was introduced into the official research team and quickly became established as the expert guinea pig and an expert technician and programmer in her own right, achieving mastery of the XO ‘surprisingly’ quickly. The research group operated under open access, and diligently published all their work, but did not go out of their way to publicise it. There were threats of the department being shut down, and everyone kept a low profile to try and eke out a few more months on their work.

Having worn and improved the XO for nearly 2 years, Gemma was used to going for long walks outside; a lunchtime urban explorer. Then Gemma was mugged, and the game changed.

By the time the police arrived, one of her two attackers was dead with a broken neck, and the other was screaming for help, holed up in an alleyway desperately fending off an enraged Gemma with a wooden post. The XO pieces were torn from her neck and one of her arms. Her head was spasming, mostly down and to one side, one eye still open, one arm in a rictus against her chest, several fingers broken, still holding the attacker’s ear. And Gemma was closing in for the kill with her feet.

It took a while before the police were satisfied that they understood the situation. Gemma couldn’t speak until she had reattached the neck fittings.

So ended the covert research. Gemma was big news. Gemma was ripped; the muscle twitch suppression had, it turned out, led to significant increase in muscle mass and definition. Gemma was dangerous. Gemma (and her team) was in possession of some seriously interesting tech.

The team opted to split up soon after, amidst many tears but no acrimony. Their work had been validated in an explosive fashion. They could take their pick of the directions their careers might go. They all vowed to continue working under the terms of open access.

Of the team, Gemma and Tech Mum wanted to take the XO into new territory, and shake off the killer babe vibe which had, inevitably, started doing the rounds. Another wanted to commercialise the tech, promising to include the entire original team in the outcome. One wanted to perfect the existing XO. One was frightened by the pace of progress and wanted to take time out.

Dad popped up again. A pal, Jem, had been invalided out of the army with brain and limb damage from shrapnel and was learning to walk again. Could Gemma perhaps help out? The timing was ideal; Gemma and Tech Mum joined the military charity for limbless veterans within the month.

Limb coordination was a simple repurposing of the same basic suit worn by Gemma. Limb replacement was a different matter. Gemma’s suit did not provide muscle power, merely provided control over the user’s muscles. Jem, the ex-soldier’s missing limb had no muscles for power, nor as a signal source. Gemma and Tech Mum had to rethink their signal processing approach, and tease out the muscle signals at least one, or two, links earlier in the path. They were forced to reconsider the nerves as the primary source of muscle signals, something they had steered away from initially. The signals were much weaker, and intermingled with those of 100s if not 1000s of other nerves. But Gemma’s body itself enabled the breakthrough. They knew the precise signals reaching each muscle group, and could then look for the nerve signal further back in the path from the spine that matched the resulting muscle control. It was fairly simple, if 6 months of hard lab work counts as simple. No new physics. Just better information and some motivated people.

Jem’s artificial leg, motorised, was soon a comfortable part of him, based on his natural leg muscle control. No new coordination to be learned once the relevant nerve signals had been identified and linked to the leg.

Having started this limb work in the army charity, Gemma and Tech Mum were invited by the army proper to continue their work in a fully-funded lab, still working under open access, still working with the war wounded and any other causes they fancied, but also taking on the occasional special request that might come their way. No pressure, but the promise was for plenty of backing and very interesting special projects.

Over the years, they embedded new skills in the suits, such as an endurance mode. Then a fitness accelerator, to simply increase muscle bulk, because of course non-disabled folk were using these suits. Gemma was uncomfortable with this, considering it demeaned the original purpose of the suit, but it brought in the money.

Gemma-with-suit had shown a natural affinity for fighting, in practice a form of Muay Thai which, once embedded in the suit, enabled the user to become proficient in days. But they soon expanded the XO suit to include most of the non-grappling forms of martial arts. The XO suit’s main weakness was pieces being ripped off, so the emphasis was on quick strikes and a solid defense. Limb replacement came to include arms and hands.

And then there was external or autonomous control. Much like a newly minted lottery millionaire, Gemma was known, and many suggestions came in for what she could spend her time on. A close school friend, Amy, suffered from debilitating epilepsy, multiple life-endangering attacks every day. By adding a fallback mode to the XO, it was relatively simple to handle a complete loss of user nerve control and bring the unfortunate Amy to a safe standing position when a brain storm struck.

Subsequent army experiments had indicated this also worked when the user was unconscious. And also conscious. Gemma had been nervous about going down this avenue, but the army had insisted it needed dealing with.The army had been good at spotting functional and moral weaknesses in the use of the XO suits. Gemma and Tech Mum had been mostly solving their own and others’ needs and assuming all uses of the suits would be similarly worthwhile. But the army knew better.

The user could fight the suit’s control, but fundamentally the contacts could overwhelm their weak nerve signals. Inevitably, the suits were online; they could be hacked and remote controlled. There was no guaranteed opt-out for the user. Almost by definition, their users had poor, if any, muscle control, so any form of cut off switch was most likely useless; they certainly couldn’t guarantee being able to rip off the contacts, or being in a functional state if they did so.

Gemma had spent many weeks trying identify which of her muscles she had sufficient control over, that weren’t already wired into the suit. She found she could maintain consistent forward pressure of her tongue on her lower teeth, and had designed a cut off switch accordingly. For each user it was different, but if, or when, the user was rendered unconscious before activating the cut-off, nothing made any difference. An exposed suit could be co-opted or revert to fallback mode.


20 years later, here she was, leading an exercise to clear out enemy-infested territory. Gemma shuddered at the thought of the other terms used to describe the ‘enemy’. The joy had left as suddenly as it had arrived. The energy bars sat queasily in her gut.

She and the team were here to combat their future. They were wearing the very best, battle-hardened tech the army could supply. The team, and especially Gemma, were the most skilled wielders of the XO tech; more effective than any non-enhanced army unit. And yet, any one of them could become the enemy.

Gemma’s HUD gave a ping, and she flicked the XO into ready-for-action mode, warming up her muscles. The rest of the team were doing likewise.

The techniques for taking down an enemy varied with each individual. The standard initial approach was to use a sticky anti-riot net to immobilise them, but even then that might lead to more harm if they fought too hard against it. The owner might not recover.

Another ping, and Gemma fired up into full combat mode, just as an enemy strode smoothly and quietly into the valley. Mouth partially open, drooling. Their eyes closed, but the head swivelling from side to side as the sensor on top steered the home-built suit towards the full battery signal Gemma was broadcasting.

She couldn’t have anyone else be the bait, since this was all her fault.