The first time, he's overwhelmed with relief. The bruises and cuts on his body fade into insignificance next to the sight of red leather and blond hair and a familiar face set in familiar determination.

"Swan," he says, and his knees almost buckle.

"Killian," she breathes, and covers the last few meters at a run. Her hands cup his face, her eyes gleaming a little with unshed tears. "Killian. It's okay. I'm here."

"You shouldn't have come—" he starts, but she shushes him before he can finish his protest.

"Come on. I've gotta get you out of here. Can you walk?"

"Aye." His back is still sore from the whip, his stance a little awkward from it, but he keeps pace with Emma as she leads him from the dungeon. She pushes open the wrought-iron door that has kept him prisoner, and waves him through into a long, dark hallway that seems to fade into the black distance.

He still feels a little light-headed, and shaking his head does nothing to clear the haze from his mind. Emma keeps a hold of his hand, but he can barely feel her touch. But she is here, right next to him. She found him. They're going home.

He doesn't know how long he's been here – time quickly became lost amid the blood and the pain and the fear. He didn't try to keep track. He never expected to leave again. He never thought that Emma might try to come after him.

He never thought he'd see her again. Even given the still-precarious situation they're in, for the first time since becoming the Dark One, he feels hope. She's here. And together, there's nothing they can't do.

"This way." Emma tugs at his hand. They run down a dark, narrow set of stairs that seem to go on forever, until at least Killian sees light ahead. It's a flickering, reddish glow, more than a little foreboding, but he'll take it over the darkness gladly.

There's a short tunnel at the end of the stairs, and then they step out into a huge cavern.

It brings to mind the Echo Cave back in Neverland, except the abyss in this one is filled with a raging inferno, the source of the ominous red glow. Killian comes to an instinctive stop, eyes sweeping the cavern. It's hot, so hot that he's already sweating. "Did we take a wrong turn?"

"No," Emma says, pointing. "Look."

It takes him another moment, but then he sees it: a narrow stone bridge leading across the chasm. It isn't a sight that fills him with eagerness. But whatever lies ahead can't be worse than what he's leaving behind, so when Emma starts forward, he follows.

He means to take the lead, but Emma stops him with a hand on his arm. "I'll go first," she says. "It's the rules. The living to lead the dead, that's what Regina said."

A tiny part of Killian's mind wonders how and when Regina became an expert on leading people out of the Underworld, but he dismisses the thought. The woman is nothing if not resourceful.

"Come on," Emma says, her smile almost giddy. "We're almost home."

She steps out onto the bridge, and Killian follows. The heat is stifling, wrapping around him until he can barely breathe. Flames lick up from below, scorching the stone and charring his boots. His wounds sting.

He keeps walking, keeps his eyes on Emma, right in front of him.

And then, without warning, a flame shoots up higher than the others, right towards Emma. It wraps around Emma's legs like a fiery rope, and suddenly the world is made of terror again.

Emma cries out and staggers. Killian lunges for her, grabbing her arm just as she falls. He's thrown to his knees as Emma slips off the edge, but he keeps hold of her.

"Hook!"

"Hold on!" he yells. Everything hurts now, his bruised knees getting scorched by the hot stone, his arms straining, his stomach wound exploding into pain again. He feels wetness on his back as the lacerations there re-open under the strain.

And to his horror, he feels his hand grow wet, too.

Emma screams something as the flames rise again, and he smells hair burning.

Her fingers are slipping through his.

"Hold on!" he yells, his voice breaking, and he reaches down with his hook, trying to snag something, anything.

But it's too late. Emma's hand slips from his grasp, and with a final panicked scream, she vanishes into the fire below.

"Swan!" Killian screams the name, a useless gesture. He moves, pushing his upper body over the edge. Maybe she found another handhold. She has magic, she's resourceful, she's Emma Swan. She can't just be gone.

But she is.

He doesn't know how long he stays there, staring into the fire that took her. The fire that should have taken him. He's the one who deserves punishment. Not her. Never her.

He screams again, a wordless cry of pain that tears at his throat. Gone.

He barely feels his body anymore. She came here to find him, and to save him. She conquered all the odds and defied death itself to come after him. He was so sure they'd make it.

Gone.

And Killian knows that the terrible, hollow, aching pain that she left behind will not fade. Not this time. He isn't going home; he no longer has one. He is dead, and he will stay dead. Even all of the agony inflicted by Hades feels like nothing, next to that.

He stares down into the fire, and he knows that there's only one thing he can still do, one choice he can still make.

One last time her can follow her.

He jumps.

"Touching," a drawling voice says, piercing through the blackness. "Really. You didn't even try to run for it. You must really love her."

Killian tries to force his eyes open, but his muscles won't obey. Even without sight, though, he can tell that he's back in his cell. Back on the cold stone floor, back with his tormentor.

"Guess it wouldn't have done you any good, anyway," Hades continues. Killian finally manages to force his eyes open, blinking away a mix of tears and blood. The bastard is sitting in the chair he always brings, legs casually crossed, the picture of smugness.

Killian has never hated someone as much as he hates the crocodile, but he thinks he might be on his way.

"Where—" He has to stop and swallow a few times before he can get the words out. "Where is she?"

"Who?"

"What have you done to her?"

"What, the blond girl you keep thinking about?" Hades asks. "She's not here. She never was."

It takes Killian a moment; his head is still spinning and the pain is distracting, but he connects the dots. "A trick," he says. "One of your games."

"An entertaining one, I've got to say," Hades agrees, with a smile. "We'll have to do it again sometime. In the meantime, though..." He runs a critical eye over Killian's body. "I'd say you've rested enough, wouldn't you? Come on, get up, you've got a date with the rack today. No rest for the wicked, as they say, eh?"

The second time, his relief is immediately tempered with suspicion when Emma unties him from where he's hanging, toes barely touching the ground. But there are no stairs this time, and no fire.

Instead, there's a wide, open room, and iron bars that slam down almost in his face, and Emma's terror as the ceiling begins to descend on her.

He wakes to Hades' smile and another round of torture.

The third time, he refuses to go, until she persuades him with inside jokes and references to beanstalks that it's really her.

It isn't until the hellhounds drag her away that he realises that Hades can pluck everything from his mind just as he has plucked Emma's image and mannerisms.

When he wakes, Hades congratulates him on figuring that out, and promises to make it harder next time.

The fourth time, he's overwhelmed with terror. It churns in his gut and freezes his heart and he just shakes his head, cowering back as Emma tries to soothe him. He can't go. He can't do it again. He can't watch the woman he loves die again.

It doesn't make a difference, in the end. Emma refuses to leave without him, no matter how much he implores her and swears that the trick won't work anymore. He thinks that maybe, Hades will give up.

He doesn't. Instead, he comes sauntering in himself, and seizes Emma. And no amount of reminding himself that this is a trick helps lessen Killian's guilt and pain and terror as he is forced to watch her endure the rack.

Waking up to face torture himself almost feels like a mercy, after that.

The fifth time, she doesn't come to rescue him, and the relief of that is almost overwhelming, too. He sees her, briefly, but not in his cell. She's standing outside, on a lawn, her eyes on him and her smile hopeful. She speaks, but he can't hear her, can't seem to move or speak or do anything except look at her. His vision blurs and flickers, and Emma disappears all too quickly.

He wakes to pain, worse than ever before. When he tries to open his eyes, only one obeys. The other is swollen shut, only good for a dull pain. He looks around, sees only an oddly-shaped chamber ahead of him with a fire dancing in the middle of it. There are no chains, no guards, no closed doors.

And something feels different.

Something has changed in him. There's an odd feeling in his chest, strange in its familiarity. It feels like a tiny spark, a stubborn little flame struggling against the darkness, warm and determined.

It feels like home.

Killian struggles to his feet with a pained grunt that turns into a growl of anger at his legs when they refuse to obey. His right ankle won't support his weight the way it should, so he leans against the wall, clutching his stomach with his good hand.

There's no sign of Emma. But he swears that he can feel the echo of a heartbeat in his chest.

"Is this a bloody trick?" he barks. His voice echoes through the room.

But there's no answer. No sign of Emma. No sign of hope. Nothing at all to justify the sudden warmth spreading slowly but unerringly through his chest.

Something has changed.

And Killian is pretty damn sure what it is.

This time, he doesn't feel relief, or terror, or anything in between. This time, there is only determination, fuelled by the steady, warm beat in his heart.

She's here. And he is going to find her.