Danny wasn't sure how long he sat there waiting for Sidney to turn up and failing to convince Shadow to help him before he decided to throw caution to the wind and start pounding on the door and yelling. The washroom wasn't that far down the hall. In theory, Sidney should hear him and rescue him.

Except he didn't.

"Come on!" Danny shouted, ramming the side of his fist against the door yet again. "Let me out of here!" What he wouldn't give to figure out how ghosts could make objects exist out of phase with everything else. Or to make himself exist out of phase with everything else.

He tried to remember what it had felt like. That might help. When Sidney had done it, Danny had been cold, but it had been different with Johnny. Hadn't it? Surely he wasn't forgetting already. Did the type of material make a difference? Was it slightly different for each ghost or for each type of ghost, depending on their powers or maybe their reason for existing?

Danny didn't know.

There was entirely too much he didn't know about any of this.

He splayed the fingers of both hands against the door and pressed his body to it, trying to push himself through what was still very solid metal. "Come on, come on."

He tried very carefully to think of coldness, and then of nothingness, and then of airiness. He tried to hold the memory of that feeling and use it to force himself through the door, or the door through him, or whichever way it worked because frankly he didn't have a preference as long as he got out of here.

It didn't work.

Crud.

"Sid, get your butt over here and help me!"

Nothing.

If Shadow were going to help, he'd have done it already, so Danny didn't really need to ask again. Besides, for all Danny knew, he wasn't going to help until Danny held up his end of the bargain and dealt with the fact that Kitty and Johnny weren't together. Shadow might miss her as well and just be holding a grudge or something.

Still, Danny wasn't exactly being quiet. Seriously, how could no one hear him from the main floor? Or even from some office or whatever else was down here besides random storage places? How could there be no one? That was weird, right?

Maybe he was overthinking this. He hadn't asked Jazz what was normal for the library here, and he couldn't even pretend to know the answer himself. What he could try to figure out was the whole 'passing through solid objects' trick. Because there had to be some trick to it if he could just figure it out.

Maybe he needed to focus less on holding on to that airy-cold-nothingness feeling in himself and more on pushing it out and into the door?

He tried that, too, plastering his body against the door and pushing that feeling into it.

No dice.

Maybe the key was not to think. He could be overthinking this entire thing and that's why it wasn't working. Maybe—

Danny fell forward.

He was too surprised to do much more than throw out his hands on instinct to catch himself. Sadly, no such instinct kicked in to stop him from slamming into the floor like whatever had stopped him from slamming into the ground earlier. It was mostly his palms and his knees that stung, but still. "Ow."

"Need a hand?" a voice above him asked, and Danny glanced up.

Valerie smirked down at him, one hand braced against the wall as she leaned over—

No.

Wait.

Not the wall.

She was bracing herself against the door.

The door that he was lying through.

He was lying through a solid door, and she wasn't freaking out.

"Oh crud—" Danny started to move, jerking back, but then all he felt was pain, exploding from his ankles in crushing searing wrongness—

The shifter—still wearing Valerie's face—smiled as Danny screamed. They crouched in front of him and raised an eyebrow. "If you think someone will come to find out what all the fuss is about, it won't help you. If we're still here by then, I'll just kill them."

Danny's scream had morphed into a high-pitched keen that finally died with the last of his breath, shuddering out of him like a sputtering engine. He tried to pull in more air with quick, shallow breaths, because everything hurt, hurt in a way he couldn't articulate because it was only pain, and every heartbeat was an excruciating reminder that the agony wasn't going to subside any time soon.

"You had help," the shifter said, "but I can be quite reasonable. If you tell me who's been helping you, I won't go after your sister."

Danny tried to pull his ankles free and black specks immediately crept into his vision, the world tilting even as he collapsed onto what he knew was a level floor.

The shifter reached out and grabbed Danny's chin, angling his head up so he could meet their eyes. He whimpered but couldn't find the strength to pull away. "I'll even help you out of your little predicament. All you need to do is sing for me. That's easy enough to do, isn't it?"

The shifter's teeth were very white. Everything else had faded to black, and the contrast seemed blinding. Were Valerie's teeth usually that white?

"I can also make your situation worse," the shifter said as their free hand closed on his right wrist. It went numb, and the shifter turned Danny's head so that he could see his arm sinking through the floor before the movement itself stole the last of his vision. "All I have to do is let go," the shifter whispered, their voice somehow still easy to hear above his thundering pulse, "so if you don't want me to do that, you should tell me the first name."

The first name. Did the shifter know that Danny had the help of more than one person or were they guessing? They could have overheard him calling for Sidney earlier, but they couldn't know about Johnny, could they?

Unless they'd been in the room with Danny, had seen and recognized Johnny's motorcycle, and had simply decided not to reveal themselves until they'd had Danny trapped.

He needed to think this through. For Jazz's sake, not just his own.

The shifter let go.

Feeling immediately came back into Danny's arm, and with feeling came a fresh wave of pain.

He screamed again—

—and then, distantly, he heard his own scream cut off abruptly, like a switch had been flipped. He couldn't scream. He couldn't feel anything, either. No pain, anyway. Which should have been a relief, and might have been, except he didn't have any sense that he could move.

He tried to wiggle his fingers. His toes. Turn his head.

Nothing.

He'd woken up and still been frozen with sleep paralysis exactly once in his life, and this felt entirely too much like that. He was helpless, still and staring without seeing through the darkness, and there was some suffocating feeling within him, crushing him, like he was trying to cram one more shirt into the last bit of space in his suitcase—only he was the suitcase and all of the things already inside of it.

When the blackness bled away from his vision and let him see again, he was flying towards the school.

Johnny.

This must be Johnny.

Shadow must have gone to get him.

Shadow wouldn't have done this himself, right?

Except Danny still couldn't feel the motorcycle beneath him, or even turn his head to look down to see if there was a motorcycle beneath him, and he couldn't hear anything, not even the rushing of the wind. They were definitely outside, definitely flying—there was no other way that he could be this high above the ground—and he knew he wasn't alone, he couldn't be, because no amount of imagination would convince him that hovering for three seconds could equate to panic flying away from the shifter like this.

Besides, if he were the one driving, he'd know where they were going.

He didn't.

So he was only along for the ride.

Except this still felt wrong, like he'd taken the backseat in his own body, and—

Oh crud.

Crud, crud, crud, his parents had said ghosts could do this, but he'd never seen it, hadn't paid attention, hadn't thought—somehow, despite how often he was around ghosts—that this might happen to him.

Then again, if controlling him were as simple as possessing him, why hadn't the shifter done it?

"Cool it already, will ya?"

That was his voice.

Those had not been his words.

The shifter wasn't in sight, which on one hand was good, but on the other hand, it meant there was entirely too good of a chance that it had been Danny's mouth moving to say those words.

More words poured from his mouth. "It's not as bad as you think. You trust me more than you trust them. You would've thrown them off before they could do whatever they wanted to do, and they know it. I figure they didn't want to take the risk."

Oh, no, he didn't like this. This was so not happening. Not even for Sidney—because it was Sidney doing this. Somehow.

No.

The shifter had stolen his face. He couldn't deal with someone stealing his actual body, too.

"It's not stealing! It's saving, so stop fighting me." Sidney huffed, and this time Danny felt the tightness in his chest, the throbbing ache in his limbs, and he had an inkling—however nebulous and inexplicable—of the effort it took Sidney to force his words past Danny's lips.

Was it wrong to be glad Sidney was having a hard time with this, considering the ghost might very well have saved his life back there?

"I did save your life back there," Sidney hissed out through Danny's gritted teeth. Danny could feel the tightness in his own jaw. "At the risk of my afterlife, too. So unless you wanna join me in that, cut the gas and chill. Least till we're back on solid ground. You keen on going from frying pan to fire?"

Falling to his death was not the preferable option unless that hovering thing kicked in to save him at the last second, and he somehow doubted he could count on that.

He'd be happier if he knew where they were going, though.

"My old haunt," Sidney said, raising Danny's hand to point one finger ahead of them. Almost as soon as Danny had noted the direction, the finger—and hand and arm and everything else—disappeared. Invisibility. Right. That made sense. Not much weirder than seeing a seemingly unaided human flying through the air, assuming anyone might see him if they looked up in the first place.

It still took Danny a moment to recognize his school from above, but the lights over the football field finally helped it click into place. There must be a game on today, but he couldn't tell from here who the Ravens were playing.

If the plan was to hide in the crowd, Danny wasn't sure it was a good one. On one hand, yes, safety in numbers, he could be another one of the faceless masses, but on the other hand? He did not particularly want to give the shifter a giant target when they liked to try to control Danny through threats. Most of the crowd would effectively be strangers to Danny, but that didn't mean he wanted any of them to get hurt.

He hoped Johnny was able to keep Jazz safe. What if the shifter had looked for her after Sidney had gotten him away? More to the point, what if the shifter had found her? Would Johnny be able to take him in a fight?

Was it possible to win against an opponent who could assume any shape, become anyone?

What if the shifter knew who Johnny was and pretended to be Kitty? Pretended that Danny had called her through?

They started to fall. Danny's stomach returned in time to turn over and swoop upwards, and a moment later, he felt the wind on his skin, catching on his hands and pulling, cushioning, except there wasn't enough of him to catch—or at least not enough to slow his fall.

Not enough to fly.

Was this kinda what flying felt like?

Danny's fascination was abruptly replaced by blind panic as his heart thundered in his ears, matched in sound by the roaring crowd gathered for the game as someone scored. The howling wind—could he call it wind if it was just him falling that was creating the wind?—seemed colder than it had at first, but colder was good, because cold felt better on his limbs, most of which were pretending they were on fire. Danny wasn't sure if it was the wind or the pain that brought tears to his eyes and blurred the world below.

Stop screaming, Sidney's voice sniped from somewhere inside of him, and Danny abruptly realized that he was, in fact, screaming.

He tried to shut his mouth, and it moved on his command.

Every part of it was dry.

Either fly or let me fly before we eat gravel, added Sidney. The ground was getting uncomfortably close.

"How?"

You thought about hovering before. Same thing. Just with movement.

Well, that was unhelpful.

That's what it is. Like it or lump it and let me do the flying.

Okay, yeah, there were definitely some more downsides to whatever this was than he'd first realized.

They'd crash before he figured this out. "I don't—"

A shudder ran through his body, and everything seemed to hurt more than it had a second earlier.

Not that he could take the time to focus on the pain. He wasn't slowing. He wasn't going to figure out how to slow. Or how to step aside and let Sidney figure this out. He was going to be smear on the pavement and—

Someone was hugging him.

They were moving sideways, not falling.

Danny opened eyes he couldn't remember closing. Sidney was frowning at him, but he didn't seem to have any trouble holding Danny, even though all he was doing was hugging him awkwardly around the middle. Danny wrapped his good arm—his left one—around Sidney's neck just in case, even though the movement didn't do any favours for the rest of his body. "This isn't what people mean when they talk about a crash course," Sidney asked slowly, sounding almost hesitant, "is it?"

Danny laughed, but that only made the pain worse. "Crash landing, maybe."

Sidney had been right when he'd said healing didn't mean it didn't hurt in the first place. It did hurt. It would be a lot nicer if this healing thing were faster.

A few seconds later, Danny felt like someone had thrown a bucket of ice water on him, and then they were inside the school. It was familiar territory for both of them, and Sidney had no trouble finding and getting them into the nurse's office to raid the supplies. Danny lay on the examination table and tried not to focus on how everything throbbed as he stared up at the ceiling and listened to Sidney rummaging around. He thought Sidney would say something about what had happened, but he didn't.

Danny weighed the options for a moment, trying to decide if he wanted to talk about everything, but he wasn't sure if he could afford not to. "What happened back there?"

A drawer slammed closed, meaning Sidney wasn't just using intangibility to dig through stuff. "Overshadowing you was the fastest way to get you out of there. If we hadn't cut out, it would've been bad news."

Right. Danny wasn't a fan of the overshadowing thing, but that wasn't his point. "Why do it in the first place if you don't want the shifter to know who you are?"

Something light fell to the floor, but Danny couldn't tell what it was without looking. A roll of tensor bandages, maybe? Gauze? Whatever it was, he could still see Sidney from the corner of his eye, and the ghost wasn't moving to pick it up.

He wasn't turning around to look at Danny, either.

"Besides the fact that you were yelling my name instead of figuring out how your powers work and using them?"

Danny frowned but didn't argue. Sidney had a right to be angry if Danny had given away his identity to the shifter. He wasn't right in thinking Danny hadn't tried to free himself, but they could quibble over those details later.

Sidney seemed to think situations that forced Danny to use his mysterious powers were useful, which might even be the real reason he'd left Danny stranded eight—ten?—feet off the ground earlier.

He did not seem to grasp the fact that Danny still didn't have the first clue about what to do, which would be helpful before being stuck in those situations.

"Look, there's no sense in splitting hairs. We both know anonymity is safer for me, and I tried to keep it. I stayed invisible even before I overshadowed you and we beat feet, I didn't head straight here when I was flying, and I kept overshadowing you till you forced me to stop. The shifter won't have had an easy time trying to tail us, and I figure they'd have been here already if they'd managed that. We've got a bit of time."

"But even if they don't find us right away, they might still know who you are now."

Sidney said nothing.

"I'm sorry."

"You needed help. I couldn't just leave you once I realized that. I thought you…. You don't know enough to pull outta what they were doing to ya. I thought you might, till they showed up and you couldn't scram."

"Right." That almost sounded like an apology from Sidney, and Danny was going to take it. "Thanks. Look, do you know if there's a way to, um…." What was the right way to put this? "I know I can heal. Is there a way to make my body do that faster?"

"You aren't missing any pieces, and any normal human would be."

That wasn't an answer to his question.

"So no, you don't know how to make it do that?"

Sidney snorted. "Eat 'n' sleep. Pain meds in the meantime. You allergic to anything?"

"I don't think so."

"Well, gambling shouldn't kill you now. With your healing and all."

Was that supposed to be comforting?

There was the distinct rattle of pills in their plastic bottles, and something—presumably those bottles—slammed onto the table next to his uninjured hand. "Figure out what you need. Don't be afraid to up the dose; you're bound to have a higher tolerance than whatever you did before. I'll go find you some grub and something to wash it down with."

Danny didn't hear Sidney leave, but he lay there for at least another ten seconds before groaning and fumbling to grab the bottles and bring them to his face one at a time. Ibuprofen and acetaminophen. Was it bad if he just took one of each? Or, preferably, two of each?

Probably.

Sidney had seemed fairly confident that it would take far more than that to kill him, though, so Danny forced himself to sit up and then shook out twelve pills from each bottle. He separated two from each pile to take once Sidney came back—he had no trouble swallowing a mouthful at once, and frankly the sooner he ingested them, the better—and then looked around the room blankly for a few more seconds before deciding to wrap the remaining twenty pills—in piles of ten—in two separate pieces of tissue and shoving those into his pocket for later.

He was not going to be optimistic enough to assume there wouldn't be a later.

Sidney had said he was lucky he hadn't straight up lost body parts after what the shifter had done, but despite the haze of pain, Danny knew he was lucky to still be able to think straight, too.

He didn't feel lucky, though.

He wanted this to be over.

Maybe, despite the risks, it wouldn't be such a bad idea to find whoever this other gatekeeper was.

He needed help, and he was beginning to suspect he needed more help than whatever Sidney and Johnny could give him. Jazz would try her best to help, too, because it was Jazz, but that just made it more likely that she'd get hurt. He'd talk to Sam and Tucker if he could, but it wasn't like he wanted to drag them into this. This wasn't their problem, and the shifter meant that involving them invited more than just an imagined danger.

If he explained more than what they already knew, what Tucker had found out and passed on to Sam and what Danny had chosen to clarify about the ghosts that were somehow escaping their realm through him, then it would only make his friends more likely to blame themselves for what had ultimately been an accident.

As much as him deliberately exploring an invention from which he had been explicitly banned from messing around with could be an accident, anyway, but at least if he kept calling it an accident, his friends wouldn't feel so bad about their part in what had happened.

And, well, it wasn't like he could explain much more about all of this even if he wanted to.

He barely understood this himself.

"I have to figure out how to control this," he whispered. "If I can figure out how to control it, then maybe I can figure out how to stop the shifter."

Between past experience and what Johnny and Sidney had talked about earlier, he thought he had some idea about this calling thing, even if it didn't make a whole lot of sense. If it was too general, then every ghost would hear it—or sense it or something, however that worked—and would, in theory, be able to come and get through. Or find him, in the shifter's case. Which was bad, for obvious reasons. But if he focused and was more specific, then the shifter wouldn't hear the call, and he might be able to get more help without tipping them off.

Danny admittedly still wasn't wholly clear on the 'only open one side of the door' thing or whatever Sidney had been trying to say, because if it was a door, it was either open or not open. He might not be as smart as Jazz—his opinion, not hers—but even he understood that.

Although, given Sidney's insistence about the one-way door thing, there was apparently something Danny didn't understand that was terribly relevant.

Danny was still staring at a particular speck on the tile floor when Sidney returned with some stuff from the vending machine. The morality of stealing junk food wasn't on Danny's radar beyond dismissing it as a worry in the wake of everything else, so he pulled on the tab to pop open the can of Pepsi and took a swig. It was sticky and sweet, but it was cool, so he took another swallow before tossing the pills in his mouth and washing them down with the rest of the can.

It wasn't food, but it was calories, and if Sidney was right, his body needed those calories to heal. Whether or not they were the best calories was something Danny could figure out on his own in the future—it's not like he planned to ask Dash for his opinion on the best protein shake while Dash was busy shoving him into a locker—but anything was better than nothing now.

He tried to tell himself that that was why he immediately ripped open a bag of chips and didn't figure out what flavour they were until he was licking the last of the crumbs off his fingers. Had all dressed existed as a flavour in the fifties? Had potato chips? He didn't even know when junk food like this had become a thing.

Right now, he didn't care, either.

Between the pain meds, the food, the placebo effect, and whatever healing thing his body was doing—because surely the pain meds and the food weren't helping already, not on their own—he was feeling better. Not loads better, but noticeably better.

He felt better enough to say, "Tell me more about the other gatekeeper."

Sidney shuffled his feet. "Already said I don't know him."

"But you know about him."

"I don't know anything that'll be useful to you. Any ghost with good sense avoids him, and I got good sense."

"C'mon, there has to be something. What can he do?"

"Just because he can do something, doesn't mean you can."

Danny frowned but decided to let it go for now. Sidney might be more willing to talk later, and there was something else Danny wanted from him now. "Teach me how to walk through walls."

Sidney's eyes widened. "I dunno—"

"You said," Danny started, because he wasn't going to let this go when it was so important, "you said I didn't know enough to get out of it. What the shifter did to me. Which means you think I can figure it out. So teach me."

"How am I supposed to teach you something I just know how to do? I'm a ghost. Passing through stuff in the human world is easy peasy. I don't need to think about it. If I want to do it, I do it. You didn't exactly pick it up when I tried to tell you how to fly, and you'd done that before."

Right. As if his previous flying experience counted when it amounted to hovering inches from the ground and he had no idea how he'd done it, either. Still, now wasn't the time to argue that, especially if Sidney was being truthful when he said he couldn't teach Danny anything. Unless he only meant he didn't know how to explain anything, which was something Danny agreed with, but that was a hurdle, not an impossible obstacle.

"Can you feel anything when you do it?" Danny pressed. "When you pass through stuff, I mean? Do you have to focus? Do you need to imagine yourself moving through it before you actually do?"

Sidney was shaking his head. "We aren't the same. You're a gatekeeper, not a ghost."

"You tried to explain about the calling thing and the gatekeeping thing; you can try to explain this, too. Please."

"Of course I know something about that. I can hear it when you call, either for me or for anyone, and I have to pass through something to get here. Doesn't matter whether that's a natural portal or a gate. But trying to teach you how to do stuff like me? That's different."

Danny pursed his lips. "Then take another stab at the whole gate thing. How am I supposed to open a one-way door?"

Sidney hesitated. "How's your biology?"

Danny had no idea how this could possibly relate to biology. "Bad."

"Baking?"

"What does that have to do with anything?"

Sidney made a face at him. "I'm trying to think of something you'll understand, okay? You ever mix oil and water?"

Danny raised an eyebrow. "Is your point that they don't?"

Sidney nodded. "One-way gates are kinda like that."

At this rate, Sidney's horrible explanations were going to be the death of him. The shifter was going to corner him, and Danny wouldn't know enough about how to do something Sidney had tried to explain to get out of it. "What?"

"Where the two sides don't mix unless you make them, so you can keep things separate. They can be kinda like a semi-permeable membrane. Or—or a two-way mirror, except instead of just seeing through one side, you can pass through it. You should be able to make a gate that will only open for certain ghosts or only open for them on one side." Sidney chewed his lip. "You might be able to do it where you can just see, too. A viewing portal, not a gate, unless you decide to make it into a gate. I don't know. You'll have to figure that out."

Well, it was a slightly better explanation than he'd given Danny before, but it was becoming increasingly apparent that Sidney's way of giving advice on how to do something boiled down to 'just do it'.

Maybe it was just as well Sidney wasn't trying to teach how to actually do any of this right now; Danny wasn't sure he'd have the strength for it even if the explanations had made perfect sense. He reached for another bag of chips, pulled open the top, and shoved a handful of what turned out to be sour cream and onion-y goodness into his mouth. "So with calling, if it's more specific, that means only a certain ghost can pass through the gate? Or only a certain type of ghost? I mean, I didn't call you specifically. I didn't know who you were before I met you." He offered the bag to Sidney. "Chip?"

Sidney looked at it longingly for a beat before shaking his head. "I miss real food, but you need it more than I do. And as for calling me…." He trailed off and fiddled with his bowtie, straightening it even though it still looked straight enough to Danny. "You wanted help. Needed it. Against a bully. I know that feeling from when I was alive. I recognized it, and I wanted to help you. After all, no one should be bullied. So when you called, I came."

Okay. That made more sense than it ever had before. Danny did remember desperately wanting help. He also remembered really not wanting anything to happen once his stomach had turned, but maybe it had been too late. Or maybe some part of him had known that letting Sidney come through was for the best. Speaking of that, though….

"And when I open a gate," Danny said, "does it have to, y'know, always be here?" He gestured vaguely at his chest with his good hand.

Sidney stared at him for a moment, and then he burst out laughing.

It was so far from what Danny had been expecting that he felt himself starting to flush with embarrassment.

"I don't know why I thought you knew," Sidney choked out. "I mean, it should've been obvious, you didn't know the first thing, so of course you don't know, but I just thought you did."

"Glad I could provide you with some amusement," Danny muttered, wishing he'd never asked.

Sidney shook his head. "No, no, it's— I mean— I forgot you don't know anything. Like, at all. Total ticket to—"

"You know you're not making me feel any better, right?"

The smile dropped off Sidney's face. "Sorry," he said, and it sounded like he meant it. "It's common knowledge for all the ghosts around my usual haunts. You centre your gate, but you can project it wherever you want. Or at least…. You should be able to with practice. Because of what the gates are, I mean. And once you figure out that part, maybe it'll be easier for you to see what you need to do when you're making a one-way gate versus when you're not."

"Really?" That meant there was hope, hope that he wouldn't have to live with this feeling inside of him for the rest of his life—or, at least, the feeling and the knowledge that if he wasn't careful, something was going to crawl up his throat and force its way free. "Okay, forget everything else, we need to work on that."

It could help him with the shifter, too.

If he could figure out how to make these gates, then if the shifter did catch him again and force him open a gate, maybe Danny could open a one-way one and shove him through.

For the first time since the shifter had come, Danny let himself hope that it was all going to work out.

It was a wonderful feeling.