He's been walking for a very long time.

At least, he thinks so. He's not entirely sure. If he thinks too hard about anything- where he is, who he is, how long he's been here- he can't quite seem to keep the ideas from slipping away from him. The more he concentrates, the faster the details fade, and he's back to walking through the never-ending gray and wondering if he really has passed that rock already, or if he's just imagining it. He's not sure why he keeps moving, only knows that he can't seem to stand still, and every time he tries to stop he finds himself walking even faster. The silence is all-consuming, not even broken by his footsteps; once (or maybe more than once) he'd tried to sprint along the path, to make some kind of sound in the gloom.

That's when he'd realized that he didn't seem to be breathing.

(He thinks that maybe he should be more concerned about that, but the idea skitters away from him as soon as it comes into his head.)

He walks, and he walks, and he doesn't know why or when or where; he walks, and he walks, and somewhere along the way he forgets to keep asking.

He's been walking for a very long time (he thinks, when he bothers to think about it at all).

"Killian!"

And now a woman is running towards him, long blonde hair almost glowing through the darkness. She's wearing a red jacket and she's the brightest, most vibrant thing in this place; she's the most beautiful thing he's ever seen, honestly, and even if he can't seem to remember much of anything right now, he feels certain of this. Her footsteps echo heavily against the stone floor as she stumbles to a halt in front of him.

"It's you," she pants, her breath appearing in small puffs in the air in front of him, and he realizes with a start that it's cold here.

He hadn't noticed that before.

Bright green eyes flick from his head to his feet, taking in every inch of him before settling on his face. Her lips tilt down at the corners as she looks at him, lines appearing on her forehead, and that's devastating, somehow. "You don't remember me, do you?"

"Believe me, love, I think I'd remember meeting you," he says, and where had that even come from? His voice sounds odd to his own ears, rusty with disuse and overloud, and he shakes his head in an attempt to clear it. The woman's shoulders slump slightly.

"What about this?" she asks, pulling a chain from under the neck of her jacket and holding out the ring that dangles from it. It's heavy silver band, a man's ring, he'd guess, although he's not sure why he'd guess that. "Look familiar at all?"

And he wants to say yes, he really does, and he doesn't know why he wants to agree with this stranger, to see what her smile looks like, for her to be pleased with him, but he does, and now he has to disappoint her. "No," he says slowly, eyes tracing the pattern on the ring, and she lets it fall back against her chest.

"Perfect," she mutters, shifting her weight back on her heels. Blowing out an exasperated breath, she runs her hands through her hair, starting to pace back and forth in front of him. "Great. And it doesn't work on memory stuff, right, because that's what you tried in New York, and that was a disaster," and he feels a jolt somewhere in the vicinity of his stomach.

"Do you know who I am?" he asks, but she ignores him, continuing to pace.

"But we have to go together for this to work, we both have to leave, or else-" She pauses, gaze snapping back to his face. "Wait. What did you say?"

"Do you know who I am?" he repeats. The woman stares at him, jaw clenched, and he can see the muscles of her cheek jump as she grinds her teeth together.

"You don't even know who you are," she says finally, and he shakes his head. "Even better. Gold wasn't kidding about this being a challenge."

"Gold?" he hisses, feeling a pulse of rage at the name before it fades back into nothingness. He frowns, because again- where had that come from?

"What the actual hell," the woman mutters. "You can remember your sworn enemy, but not your girlfriend?"

"My what, love?"

"Never mind." She eyes him speculatively, crossing her arms. "Let's try that again. Does 'Emma Swan' ring any bells in there?"

"Emma Swan," he repeats, rolling the name around in his mouth. He doesn't miss the way she's staring at him, how she catches her breath when he speaks the name (her name?), how he can almost feel the waves of longing rolling off of her as if they were a physical force. Just looking at her makes his chest ache, he hasn't felt anything like that since-

-watching her vanish into a swirling cloud of darkness; finding her in the forest with a heart in her hand and terror in her eyes; telling her he loved her, past tense, while she breaks in front of him, and hoping like hell that he'll be able to use the present tense sooner rather than later; hearing her screams as he was pulled away from her, down, down, down.

"It's you," he says, and he knows he's echoing what she'd said before, but Emma Swan is standing in front of him, glowing like the sun in the middle of endless gray, and he's torn between how are you here and you're here and I knew it wouldn't be goodbye and thank gods it wasn't goodbye. "I knew you'd-" but it's already slipping away, he can feel something leaving him but he's not sure what it is now, and what had he been saying?

"Killian?" the woman says, sounding miles away (and that's not right, because she's right there, he can almost feel her breath on his skin but he can't seem to hold her in his line of vision between blinks), and he looks up at her slowly.

"Pardon?"

"Damn it," she snaps, gritting the words out between clenched teeth, "this is unbelievable." She spins on her heel, stomping away from him and muttering incomprehensibly under her breath. Her hands are in her hair again, fingers tugging at the strands as she walks, pacing back and forth but never straying more than a few feet from where he's standing.

Where he's... standing.

Not walking.

The fog in his head lifts slightly, just enough to focus on the woman in front of him (again, he thinks, focus on her again) and he has the vaguest sense of deja vu, because- what had he been saying, before?

"Who are you?" he asks as she turns towards him, and her face crumples slightly. "To me. Who are you to me, lass?"

She hesitates, letting her hands fall away from her head, and she smiles (but it's wrong, this smile; it makes him want to reach out and smooth away the lines on her forehead with his fingertips, to cup her cheek in his palm until her eyes don't look so achingly lonely). "Someone special. You and I, we are- were- are close."

"I'm sorry," he says, the words springing out of his mouth before he can process them. "I can't seem to remember anything, these days."

"Right. Right." She nods, almost to herself, and hooks her thumbs through her belt loops. Rolling her eyes to where the ceiling should be (the arched walls on either side of them vanish into a haze of mist above them, and it's somehow claustrophobic and awe-inspiring, and he's really not sure if it feels like a cave or a cathedral), she tilts her head to stare straight up. "Is this some sort of karmic justice trying to kick my ass? Because you know, out of all of the amnesia we've experienced recently, I was only responsible for one time." She kicks the nearest wall. "And I gave all of the memories back!"

He can't help chuckling at that, though it feels strange in his throat. The woman whirls to look at him, letting go of her belt loops and bringing her hand to the ring on the chain around her neck. Tilting her head, she narrows her eyes at him, and her mouth thins into a determined line.

"Right," she says again, sucking in a deep breath. "It's probably worth a try, right?" He doesn't respond, but she doesn't seem to expect him to; she takes another deep breath, brushing her hair out of her face, and starts towards him. He stumbles backwards slightly but she continues, easily covering the few steps between them. She grabs the lapels of his coat, yanking him towards her, and presses her lips to his.

For a moment, nothing happens, other than a wild wobble for balance as he catches her against his chest.

Then he's burning , her touch scorching through his jacket, heat spreading along his body from every point of contact between them, and he's gasping for breath, air stabbing at his lungs, and he knows, he knows-

"Emma," he breathes, and she smiles against his lips, tightening her grip on him. He pulls her even closer, winding his arms around her and inhaling her familiar scent.

She's here, and he thinks he might be drowning.

(But it would be bad form, he's pretty sure, to die when he's already in the Underworld; it would be especially bad form in front of Emma Swan, when she's already had to watch him die. Twice.)

"Told you I'd find you," she says, and his eyes snap open. Shifting a step back, he meets her gaze, horrified.

"But we're in-"

"-the Underworld, right," she finishes, raising an eyebrow at him. "Thought we had that pretty well covered."

His stomach clenches. "Emma, love, tell me you didn't do anything-"

Emma cuts him off with a shake of her head, lifting his hand and pressing it to her chest. "See? Still up and running," she says, the thud of her heartbeat steady against his palm, and he thinks about letting his knees buckle with relief but pulls her close for another kiss instead. She melts into him, tilting her forehead to meet his and peering up at him through her eyelashes. "Not that I don't appreciate making up for lost time- and believe me, I'm planning for us to thoroughly make up for it- but we've got a schedule to keep."

"A schedule?"

"More like the vague outline of a plan, I guess, but I think-" Emma pauses, glancing down at a thick band on her wrist, and she winces. "Yeah, we're running behind, we've got to go."

"Clocks work in the Underworld?" he asks, amused, as she takes his hand and begins leading the way down the path.

"Not a clock like you're thinking, no," she says, holding up her wrist to show him the symbols weaving across the face of something that, if not watch-shaped, looks somewhat watch-adjacent. "Luckily Belle knew what to look for, she found something in the library from Rumpelstiltskin's old castle. Had to track it down though, and then it took ages to barter for it."

Ages. He looks her up and down more carefully as they stop for a moment, Emma pulling out a compass and holding it flat in her free palm. She looks much like she had the last time he saw her (her parents holding her back as she struggled to reach him, her hair and skin and eyes returned to their usual blaze of color rather than the icy blankness she'd been sporting for far too long as the Dark One), but harder, thinner. The delicate bones of her face appear more prominent, and her hand feels unsettlingly small in his, and with their differing lifespans they've always had a different idea of what ages means, but- "How long have I been here, love?"

"Too long." She squeezes his hand. "This way. We're going to have to run for it, I think, I doubt Regina can keep them occupied much longer-"

"Regina? She's here?"

"Everyone's here. Well, not Gold, obviously, but my parents, Robin, Regina, Belle- even Merlin was tagging along for a while, but he had to go back to Camelot-" He stops in his tracks, trying to process this- that they came for him, just like they'd all gone after Emma- and she tugs him along with her, not breaking stride. "I'll tell you everything, I promise, but first we've got to get out of here."

"Right you are," he says, matching her pace as they hurry onward. The heavy fog begins to lift as they walk, light slowly piercing the gloom, and he could almost swear that the faint smell of the sea is drifting towards them, growing stronger and stronger.

"And left here-" Emma says, eyes trained on the compass in her hand, "-and...here we are." She slides the compass back into her pocket, picking up speed. "All we have to do is cross the bridge, and then we're home fr-"

"Emma, Emma, Emma." A voice curls around them, quiet and cultured, and Emma jerks to a halt. "You disappoint me, my dear."

"Fuck," Emma hisses. She glances over at Killian, her grip on his hand so tight that it's rapidly becoming painful. "You know that vague outline of a plan I told you about?" He nods. "This is where it gets complicated."

He can't help quirking an eyebrow at that. "Gets complicated?"

She flashes him a smile, but before she can respond, a man appears a few feet away from them in a burst of flame. Shoving Killian behind her, Emma raises her hands defensively. "What are you doing here?"

"I might ask you the same thing," the man says, coming to a halt in front of them, "but I don't think either of us is in the habit of asking obvious questions. When your charming family started getting a bit, ooh, fidgety, let's say, I started to wonder what sort of herb gathering could make you so very late for our appointment."

"Not much grows around here, buddy," Emma mutters, but the man ignores her.

"And when my darling wife finally gets away from her mother and comes to meet with us, who does she find waiting at the bridge with three unconscious Reapers, but your little friend Regina?" He laughs, high and cold, and a chill races down Killian's spine as Emma stiffens. "She seemed rather reluctant to leave, but you know my wife- she's very persuasive."

"She's something, all right." She steps closer to Killian, her back pressed to his front. "And I'm guessing that once she persuadedRegina to leave, she told you to come see what you could find?"

"Precisely." His eyes glitter eerily in the dim light. "Now, why don't you hand over my property, and you can be on your way?"

"He isn't yours to keep. We've paid your price, now you have to let him go," Emma says, and Killian's heart drops.

"Emma, what've you-" Killian begins, but the man cuts him off.

"I don't have to do anything, Emma," he snaps. "You forget that down here, it doesn't matter who you are. Savior, princess, hero, villain- none of it matters, not after you cross the bridge."

She lifts her chin defiantly. "You can't touch me."

"No, but I can touch him. And you don't want that, do you?"

"If you lay a finger on him, you'll regret it for all eternity," she snarls. Killian can't see her face, but he can almost picture her expression. She's seething, angry in a way that he's only witnessed a few times, and the air around them crackles with magic. The man's eyes widen, eyebrows nearly vanishing into his hair, which- Killian blinks a few times, just to be certain- now seems to be on fire.

"Is that a threat, my dear?"

"It's a promise," Emma hisses. "Get out of our way."

"I was hoping you'd say something like that," the man drawls, a cruel smile curling across his face. Emma laughs, but it's nothing Killian has ever heard before; he can almost taste gunpowder on his lips, can feel the hot anger pouring off of her. "As you wish, Emma."

He vanishes.

Emma whirls to face Killian, kissing him with more teeth than finesse. "Killian, listen to me. We're going to have to run. Whatever happens- whatever you hear- don't stop, and don't look back."

"You're out of your bloody mind if you think I'm going to leave you down here for one instant," Killian snaps, and she shakes her head frantically.

"I'll be fine, it's all going to be fine, but you have to get out of here, okay?" Her hands cup either side of his face, eyes blazing. "Promise me. Once we get over there, you can't stop, and you can't turn around until I tell you."

"Emma-"

"You have to trust me," she whispers, pressing her forehead to his, and he can feel her shaking as she inhales sharply. "I can't explain it all to you yet, he'll be back any second, he just likes to play with his food, but- Killian, I promise, if you just trust me, everything will be fine."

"I'm not going to-"

"You trusted me, once," she says. "Before the Darkness, before- all of this. You trusted me." She blinks, and tears catch in her eyelashes. "I know that it's a lot to ask, after everything, but please, you have to trust me."

"Of course I trust you, Emma," he whispers, and she chokes on a laugh.

"Then promise me."

"I'll do as you say," he says finally, and she presses another kiss to his lips.

"Good. Now follow my lead, and when I say run- run."