A Demonic Relay

Prompt from Eiiri’s Prompt Foundry, “Pride 2 Disability Boogaloo”.

The demon coalesced at the sound of the door creaking. It was the middle of the night. Why would its jailers venture here so late?
Then it recognised the figure shakily walking across the workshop, and growled.
“Heh. Fair.” She said, her voice hoarse and uneven.
She rested both hands on her cane and stared broodingly at the swirling, etherial being trapped in the bronze containment circle.
It twisted and pulsed, producing rasping like a grasshopper had learned to form words. “Come to mock me?”
“No. I…” She paused. “Apologise is the wrong word. But admit we were wrong.”
Sudden stillness. Its eyeless gaze now barely itched. Pleasantly surprised?
“For the record, I’m not happy about you lurking in my body. However… it’s become clear that what we thought were signs of your possession were actually being suppressed by you. Everything’s gotten much worse since you were exorcised.”
She held up a hand and grimaced at how it wobbled. “Shaking. Spasms. Exhaustion. Dizzy spells. My voice going funny… Struggling to walk… And things keep looking like they’re wobbling in the corner of my eye. I fear I may be going mad.”
“You’re not.”
“You sound very confident.”
“I can taste thoughts. Yours aren’t swirly. They just can’t reach.”
“Hm.” She stared down at herself. Digesting this. “What were you doing, in my body?”
“Existing. Physical existence is fascinating.”
She waved this aside. “Why was everything easier before you were exorcised?”
“Oh. Your thoughts try to reach into your body, but there’s gaps. So I ate them before they fizzle, and made your body do what they said. I hoped you wouldn’t notice.”
“I… think I didn’t. For quite a while. When did you slip in?”
“I’m not good at time. It’s too physical.”
“Mm.”
It condensed, curling up into a dark mass about the size of her head. “You fell asleep under a tree. I was in the tree. I moved to you. The first thing I remember us doing… you woke up. You had a book with you. Full of talking animals and motor cars. We walked home and had salmon pie, cold from the fridge, and blackberry cobbler fresh from the oven. It was amazing.”
“Which bit? All of it?”
“Existing. Having senses. Tasting thoughts.”
“Hm.” She tilted her head. “Were my thoughts already ‘fizzling’?”
“Yes. Less, then. The gaps grow. Like strings wearing out.”
She digested this.
“I don’t think that’s because of me.”
“No.” She sighed. “I don’t remember that day, but… I’d been struggling. Tired all the time, dizzy spells when I exerted myself, my vision was getting blurry… and then suddenly it was all better. I was thrilled. Thought I was… over whatever it was. But actually you were just… lurking in my spine, passing messages for me?”
“Yes.”
“Mm. Why were you in the tree?”
“It was growing on a burial mound. When the roots made it into the body I was sealed in, I could slip out. But I was too weak to go far. And tree thoughts aren’t very nourishing.”
“Trees think?”
“Blandly.”
“Huh.” She firmly shook this tangent off. “And why were you sealed in a body?”
“I was pulled through, into it. He wanted to be the greatest warrior alive. I helped. But when his soul left I was still locked inside.”
“How long were you 'helping' him? Days, weeks, years?”
“Years. We had a child, and she was nearly full grown when we died.”
“And did he ever develop these ‘gaps’ I have?”
“No. I just made him stronger. Kept him going when he got tired.”
“How did he die?”
It undulated. A shrug? “Arrows.”
“Hm. Alright.” She stared down at the runes. It shouldn’t be able to lie. Which meant… “So, a warrior summoned you to the mortal realm hundreds of years ago and sealed you inside his body, you spent who knows how long in a tree, then tagged along with me?”
“Yes.”
She slowly nodded. Digesting all this.
“You were the most fun.”
“Really?” She managed to raise an eyebrow. “I wouldn’t say I live an exciting life…”
“You think. So much. It’s delicious. Especially reading.”
“Fair enough.” She took a deep breath. “If I let you out… let you back in… would you be able to help like you did before? Have, have the ‘gaps’ gotten a lot bigger since?”
“They’re much the same. The strings wear out slowly. It could be like before.”
“Except now I’d know about you.”
“Yes! We could talk.”
“Why didn’t you talk to me at the start?”
“I’d forgotten how. And then… I thought you’d be upset.”
“Well… you weren’t wrong, but it would’ve been much easier to cope with if you were honest with me.”
“Ok. Honest and talking. And helping. And existing?”
She looked down at the circle again. Considering. Then she shuffled forward and put her feet across several runes, poking her cane into the circle itself - and the demon leapt through the gap and hit her in the chest like snowball of pins-and-needles.
For a moment she floundered, her entire body fizzing. Then everything settled. Not just the fizz, but the tremors. The spasm in her left foot. Her throat no longer felt stiff. Her vision seemed to be behaving.
Slowly, carefully, she raised a hand and flexed it. Yes, there was definitely… a flicker, between intent and movement. Not long enough to call it a pause. But the movement itself was smooth and controlled, exactly as she’d willed.
“Hm.” She pursed her lips - and the expression was effortless, her face shifting as one rather than muscle groups fighting her. “I still feel very tired.”
Less tired tomorrow, now thoughts not straining.
“Ah. Good. But we need to be on the run by then.”
What?
She coughed and endeavoured to sound contrite. “They said I was absolutely not to do this.”
What??
“Don’t worry, my bag’s already packed…” She strode out of the workshop, head held high - and full of reproachful demonic grumbles.

Prompt was “Neurological Disability”.