Quite excited about sharing this one. It's my first multi-chap in a long time, estimated around 15-16 chapters long. I want to be clear that this isn't my official theory for season 5, I'm in no way clever enough to come up with something like that (although it's got to be something around Will's link to the Upside Down right?), this is just a loose theory in which I can explore character relationships and trauma.

I really hope you enjoy it. If you do, reviews are always massively appreciated :)

1.

That night, back in their old house in Hawkins, none of them sleep well.

With the absence of furniture, everything having moved with them, it could be easy to blame his discomfort on the hard floor he's laid on, a rolled-up jacket beneath his heads as a pillow. But Will knows it's not the lack of mattress that's making his spine tingle and his stomach feel like someone had pulled the floor from beneath him.

Although this house was filled with bad memories, when in California he had managed to focus on the good times here instead. He and Jonathan turning the stereo up loud, his mom complaining at their choice of song but singing along anyway when she thought they weren't listening. The three of them watching movies and drinking hot chocolate way past his bedtime because Will had copied Dustin's trick of turning the clocks back and Jonathan hadn't the heart to point that out to their mom. His friends only a short bike ride away, always primed for an adventure be it fictional or real. Mike turning up at the door unannounced, bag of sweets smuggled in his backpack, and being allowed to stay for a sleepover every time.

But now, Will's back and those things seem less like a memory and more like a dream. It's hard to remember this house as the family home it once was. The Upside Down has infected Hawkins like a disease and Will along with it. It's hard to remember anything that happened here that wasn't bad.

At around one, there's a quiet knock on his door and then El peeps around it, her newly shaven head making her look smaller and younger than ever. He sits up to greet her. She'd been sent to sleep in Jonathan's room, while he decided to share the van with Argyle until his friend headed home.

"He's alive?"

It's obvious who she's talking about. He stares at her silhouette, eventually bowing his head. "Yes. I can feel him."

El's silent. Through the dim light in the room, he can barely make out her face, but he knows the solemn expression she must be pulling.

Wordlessly, he smooths out the blanket he's lying under, salvaged from the back of Argyle's van and coated with crisp crumbs and tobacco, and pats the floor next to him, offering her half of the blanket. She accepts and lays down beside him, both on their backs, their knuckles grazing together as they share the space.

"Papa was right," she says.

"What do you mean?"

"I wasn't ready. I wasn't strong enough to kill him."

"El-" He trails off, unsure what he can say to reassure her. He'd noticed the foreign tone to her voice, the anger, directed at herself as much as Vecna. "You did all you could. More than any of the rest of us could even try-"

"Not enough."

He sighs, feeling himself shrink into the floor as he does so, succumbing to the prickling in the back of his neck. "He's injured," he says, voice quiet. "He's weak, he doesn't have the strength to hurt anyone else right now. That was you, El. You did that. You bought us all time to figure out how we can help you fight him."

She wriggles, turning over onto her side to face him. "I can't find him," she says. "I can't fight him if I can't find him."

"You can't find him? You've tried?"

She nods.

"El, you should have told me, I could have been there in case anything went wrong."

"I looked for Max too," she says.

His heart thumps against his chest. "You did? Did you find her?"

Her lack of reply is an answer itself. His body suddenly feels inexplicably heavy, but he manages to drag his hand across to hers, locking their fingers together. She'd once told him having something firm to grip onto makes her feels safe. He kind of gets it.

"001 has her," she says, with certainty. "And he's hiding."

"Then we find him," Will replies. "We find him and we find Max."

El's fingers squirm in his. "How?"

He doesn't have an answer.

Their hands separate and she rolls away, putting her back to him. He tenses, waiting for her to get up and return to the other room, to leave him on his own. But she doesn't, and eventually he repositions himself too, hoping for sleep.

He's dozing, groggily, barely still under the blanket, when there's a loud shout from elsewhere in the house. His eyes snap open. El's already on her feet and heading out of the door. He follows her, a little unsteady from the abrupt awakening. In the shell of their house, the yells echo, bouncing off the bare floorboards and leading them to the source.

In his mom's room, Hopper's grappling with a blanket, shouting something indistinguishable, deaf to the reassuring words being offered by his mom. Will recognises the symptoms from the worst of his own dreams. He watches as Hopper kicks out, trying to escape the final hold of sleep. But El dashes forwards, only narrowing avoiding a fist to the head.

"Dad? Dad, what's wrong?"

Hopper swings around to face her, terror etched across his face.

"Dad?" She lays a hand on his arm.

"No!" he shouts

"What happened?"

He's trembling head to toe. "Get OUT!"

She pushes forwards, trying to pull him into a hug.

"Out, I said!"

El stumbles backwards, with a sob.

Across the room, Will's mom meets his eyes. "Get her out of here," she says, softly, her voice a stark contract to Hopper's growls.

He steps forwards, his hand linking with the crook of her elbow. "Come on, let's go."

She doesn't move.

"El," he says. When she turns around to face him, he sees the tears on her cheeks. He gives her arm another gentle tug and this time she follows him.

He takes her back to his bedroom. They sit on the floor leaning against the wall, him crossed legged, her with her knees pulled up to her chin.

"What was wrong with him?" she asks, at a whisper.

"A nightmare probably."

She looks up at him through damp eyes. "Adults get nightmares too?"

"Yeah, I guess so."

"I should be with him."

He knows she's thinking of the times they've got through tough nights with their own nightmares; her, curling up against him to ground him in reality; him, with mugs of hot chocolate and reading out loud from his book to distract her from the memories.

"My mom's there, he's not alone."

"I should be with him," she repeats, the emphasis changed.

Morning comes, just like always, no matter how long it seems to take. At some point, around the time the sun started to make an appearance, they moved from the bedroom to sit up on the kitchen counters, usually forbidden but now the only alternative to the floor. Neither of them speak much; not uncommon in itself, but not usually without the backdrop of the TV or a tape or the hopeful chatter of his mom. Occasionally they share a glance, sometimes the nudge of a shoulder or squeeze of a hand, checking in on each other, seeing how they're coping.

After a while, the front door opens, revealing Jonathan rubbing at his eyes. With a nod, he joins them in the kitchen and starts rummaging through the cupboards.

"Seriously, no coffee?"

"What did you expect? We took everything with us."

Jonathan slumps against the counter. "There always used to be something at the back of these cupboards if you looked hard enough."

Will shrugs. Times change.

"Argyle's still asleep," Jonathan tells them. "You'd think dealing with all of this for the first time would make it harder to sleep, yet somehow…"

"I have a pretty good idea how," Will says.

Jonathan gives him a look. "We didn't smoke anything last night."

"Good."

If there's one good thing out of Argyle's excessive drug use, Will supposes it's that people are less likely to believe him if he lets slip anything that's happened over the past few days. It would be far easier to believe he was high than telling the truth.

"Listen, bud-" Jonathan starts, interrupted by the opening of a bedroom door.

All three of them look over as Hopper strides into the room, his mom right behind.

"El," Hopper says, "kid, I'm sorry."

Will feels El edge closer to him.

"You shouted."

"I know. I know." He runs a hand over the back of his head. "Can we talk? Just us."

For a second, Will thinks El is going to refuse, but then she pushes herself off the counter to go and stand in front of him.

"Talk. Not shout."

"Yeah. Yeah, promise."

They leave. Will hears a muffled I didn't want you to see me like that, and then the click of the bedroom door.

"Is there any coffee?" their mom asks.

"What did I miss?" Jonathan asks at the same time.

In a constant hive of comings and goings, their front door opens again. This time, Mike, Nancy and Robin. Will's eyes are drawn to Mike, just as they always are, so he notices the moment Mike spots him and the small smile as he does so. His chest flutters.

Will remains seated on the edge of the kitchen worktop, waiting patiently as Jonathan greets Nancy with an awkward half-hug half-kiss and then leads her and Robin over to the other corner of the room, leaving him alone with Mike.

He gives his friend the best smile he can manage under the circumstances. "Hi."

"Hi," Mike says. "Where's El?"

The smile drops from his face. He probably should have been more careful about letting it show, but it's not as if Mike would notice these days anyway. "Talking to Hopper." He jerks his head in the direction of the bedrooms.

Mike moves as if to go that way.

"I, uh, think it's private."

"Oh. Right. Hey, pretty rad he's still alive after all this time, right?"

"Yeah, pretty rad," Will echoes, dryly, thinking of the previous night.

Mike twitches as if he's finally realised something's off. "I only asked because we brought breakfast," he says, lifting the bag in his hand. "Asked where El was, I mean. I got her favourites. And, um, we brought some of mine and Nancy's old clothes too so you can all have a change. She's got them. And there's more stuff in the car. We found on old blow-up bed. Just the one, so I'm not sure who'll use it, but we thought it might, you know, help?"

Will glances into the bag and sees the familiar Eggo logo. "Thanks."

"It's nothing," Mike says, with a shrug.

He dumps the bag onto the kitchen counter where El had been sat. Will realise he's still perched awkwardly on the edge and slides himself off, suddenly face to face with Mike, there having been less space to stand than he'd realised. Mike steps back.

"Are you okay?" his friend asks. "You know, now you can feel the mindflayer again?"

"It's not just the mindflayer though, is it?" he replies. It comes out sounding bitter and he notices Mike's face change at the tone. "Yeah. I'm fine."

"You don't sound it."

Will swallows, locking his feelings away. "I'm just tired. I'm fine, Mike. Honestly."

"Okay, well, we've called a meeting. Well, Nancy has. Steve and Dustin have gone to fetch Lucas, everyone will be here soon."

"A meeting?"

"Yeah. To plan what our next move's gonna be."

By the time Will's showered and back in the main room, hair still wet, everyone else has arrived. Mike's talking to El now, so he sits down beside Dustin, who's sat against the wall beside Lucas and Erica.

"Ready for this shitshow?" Dustin asks him.

"What do you mean?"

"C'mon, Will, none of us have a clue what we're doing! Not one of our plans has worked out so far."

He stares at his friend. Dustin always has an idea or a brilliant bit of science to get frustrated over when no-one else understands it. Will's heard about Eddie, knows that Dustin was there when he died. but it still shocks him to hear him sounding this defeated.

"That's not true. Our plans, they have worked, it's just- something else always comes along after."

"Exactly." When Dustin looks up at him, his eyes are glistening with tears. "Always something."

"We've still got to try," Will says, but it's as if the defeat is contagious. He pulls at a loose strand of wool on the cuff of jumper he borrowed from Mike. Although it's old, outgrown, it's still too long for him in the sleeve and he can ball up his fists inside it without anyone seeing.

"Why'd you make me come here if you can't be arsed to come up with a plan?" Lucas asks suddenly. He doesn't look up but it's clear his question is directed at Dustin.

"Technically that was Steve, man, not me." There's a pause. "You need to be here. We need to all be together."

"We're not though, are we?" Lucas snaps. He shakes his head, still staring down at his knees. "I knew I should have stayed with Max."

Will studies Lucas's profile for signs of an update on Max. But his head is dipped and all Will can see are the bruises across his cheekbone and the scab on his bottom lip. "Any change?" he asks.

Lucas shakes his head. "Not when I left. Who knows what's happened while I've been here!"

"Lucas, you can't spend every hour of the day there with her," Dustin says.

He finally whips his head around to face them. "I wasn't there for her when she needed me. I'm not going to make that mistake again, okay?" With his palms against the floor, he pushes himself upright. "Erica, come on."

But before he has chance to go anywhere, the two adults are in the room. Hopper clears his throat, but his presence alone, albeit a smaller, less intimidating presence than before, is enough to make them all fall silent. Lucas sighs and slumps back down. Mike takes the space on Will's other side, hand in hand with El.

They roughly form a circle on the floor, legs too long to be sat comfortably crossed legged, some stretched out in instead, others folded into shape, knees jutting at awkward angles. At first, they stare at each other, waiting. It's Nancy who breaks the silence.

She pulls a notebook from her back and flicks through the pages. "I made some notes," she says. "That's if no-one minds me, er, taking chair."

"Go ahead," Robin says, sounding almost amused.

"Well, the way I see it, we have three main goals." She places her notebook on the floor in front of her, flattening the pages so it stays open. "One, find Vecna, kill him for good this time. Two, close the cracks between our world and the Upside Down, therefore stopping the Upside Down leaking in. And three," her eyes flicker towards Lucas. "Get Max back. Are we all in agreement?"

"Well, yeah," Steve says. "But how?"

Nancy glances at the notebook. "I hadn't got that far. El, do you think you could close the cracks?"

"I can try," El says.

"No, she can't," Mike and Hopper reply at the same time.

"It used up too much of her energy just to close the gate," Hopper elaborates. "Not happening."

"If I practice," El says, slowly, "I can try."

"Hang on," Dustin says. "We know it's a Hive Mind. So maybe we don't need to do all three things. We just need to do one, and the others will follow."

Will manages a small smile at his friend sounding a bit more himself.

"Vecna is the catalyst," Dustin confirms, slapping his hand down on the floor. "We kill him, the gates close. We kill him, we save Max."

"Great, Henderson. Except we have no idea where Vecna's hiding." Steve tuts.

Nancy scratches a line through something in her book. "So, revised goals. Number one, find Vecna. Number two, destroy the asshole."

"What if we don't need to find him?" Mike asks.

Mike shoots him a sideways glance and Will suddenly knows where this is going. His stomach lurches with dread.

"Piggyback," El says, so quietly that he doubts it stretches to the other side of the room.

"Yeah," Mike says, turning to the room. "When Vecna was possessing Max, El got inside her mind to fight him that way, right?" He pauses to a few nods and confused glances. "So we do the same, except this time through Will."

"Through Will?" His mom's voice is already not far off a shriek. "Has this- this Vecna-?"

"Not like that," Will interrupts. He draws his knees up to his chest, shirking under everyone's gaze. He can't help but feel betrayed. It's not like he told Mike or El to keep it to themselves, but he'd have preferred to have a bit longer of not feeling like a freak again before everyone else found out. "I'm not… he's not possessed me, okay? I can just feel him. In the back of my head, like before."

"Baby, why didn't you tell me?"

As if it wasn't bad enough that his mom's called him Baby in front of everyone, he can tell she's itching to get up and come over to his side too. "I didn't want to worry anyone," he says, uncomfortably. "It's not like I have any insight that's actually going to help."

"But you might," Mike persists, "you said you knew what he was thinking."

"You know what he's thinking?" Erica sounds in equal parts fascinated and horrified.

"Not- not exactly. Not, like, word for word. It's more just… a sense, an emotion. I don't know how to explain."

"And what is that emotion?"

Jonathan is leaning forwards, his elbows on his knees, meaning the leg that's bouncing is making his entire body shake. His eyes pierce Will's even from the other side of the room.

He maintains the eye contact with his brother and pretends this is just another of their chats. "Anger," Will says. "He's angry. He wants revenge on everyone who- who hurt him." He notices Nancy, next to Jonathan, flinch slightly. It tightens his resolve not to look at El just yet. "But he's weak, so he can't, and that- that's making him even more angry."

"You can feel all that?" Lucas asks.

"Yeah." He wraps the loose thread from the jumper around his finger and pulls it so tight it hurts. "But I don't know where he is or how we can kill him. Nothing useful, like I said."

"It is useful." El's voice is quiet, but she still manages to grab everyone's attention. "If something changes with 001, you'll know."

It's true, despite how much he wishes it wasn't. "Like a spy."

Everyone else in the room seems to approve of that, completely missing the bitterness in his voice. But he senses Mike edge closer to him and next thing he knows, a little finger nudges against his on the floor. It's not quite the handholding he once would have got, but it's enough to show him that Mike remembers what happened the last time he was used as a spy. It's enough to prove that Mike hasn't stopped caring about him altogether.

"But what about Max?" Lucas's voice cuts through the silence with its desperation.

"I think 001 has her- her soul," El says, slowly, looking at Will to check she's got the word right.

He shrugs. This is her theory, not his.

Lucas's expression is pained. "Like a prisoner?"

"Yes. A prisoner. I kill 001 then Max is free."

"Are you sure?"

El flinches slightly at Lucas's tone. "I think so," she says. "The piggyback… maybe then I'll know for sure."

Will feels several pairs of eyes move onto him, but he doesn't meet any of them, instead staring down at his knees, wishing he was someone else. He wants to rescue Max, of course he does, and no-one except maybe El wants Vecna dead more than he does. But the thought of having someone inside his head with access to all this thoughts and secrets fills him with a different kind of dread.