Hello all!
This is Ari's attempt at real Kuroshitsuji fanfic - that is, multi-chapter, not-a-random-headcannon fic.
Definite Sebastian/Older!Ciel (he's seventeen) with something that could be Ciel/Lizzy, later… this story has a mind of its own. I tried to keep them as in-character as possible, but criticism is very welcome.

Warnings: As usual, dark. Very dark, this time.

Disclaimer: Not mine. Yana's.

Seven years later, Ciel Phantomhive couldn't forget the smell.

Not the pain – that had faded in his memory to a dull blur. Nor the sights – though it was true that masked figures still haunted his dreams.
No. It was the stench of his own burning skin beneath the branding iron that still lingered under his tongue, heavy and cloying even when the dreams ended. Even in the nightmares, there was no pain, but that horrible scent, as he burned away before his eyes, silent screams, and as he awoke, he scarcely noticed that his voice had returned –

"Sebastian!"

And he awoke looking for something to cling to.

"Master." And of course, he was there, and Ciel hid his face, shame and fury both staining it. "Was there something you required of me?"

He scowled, more annoyed with himself than with the demon. "N – No. Don't be foolish. It was merely a nightmare, that's all."

Sebastian raised an eyebrow. "It seems to have upset the young master considerably."

He turned to one side, away from both the servant and the candles he held. "Know your place," he said, but didn't give it the force of an order. "It's none of your concern…" His voice trailed into silence. It seemed even now, the candle flame mocked him. Suddenly, the room was full of memories, reaching to seize him and pull him under.
Ciel didn't know if he'd ever come back up.

"Sebastian," he said, still refusing to meet his eyes. "What will happen if – when – I finally lose my grip?"

Melodious laughter. "Why do you worry about such a thing, master?" As though he knew what had prompted this, Sebastian set the candles down on a nearby table. His voice was lightly amused, but his eyes gave him away – for a slight instant, they were the color of embers.
Ciel sensed this without needing to turn. Even without the mental link the covenant had forged between them, the seven years at the other's side had instilled a deep knowledge of anything he felt, if demons could feel.
They truly did belong to each other, in every way.
It was this knowledge that allowed the seventeen-year-old Earl to speak.

"I hardly know what is real and what is nightmare anymore," he said, a slight break in his voice. "Someday soon… the two worlds will blur together entirely."

"Are you afraid of what will happen, then?"

"I am not," said Ciel, cold determination shining somewhere within him. It had climbed through anger and left behind fierce pride. "I have clung to life without fail for seven years. Clinging to reality is no different."

"We will see," said Sebastian impassively. "But you forget something, bocchan." He smiled when Ciel finally looked back at him. "It does not matter how far you may fall into insanity, or how far your wounded soul is pushed over the edge. After all, I am by your side forever, at your command until this final game ends – no matter what may happen."

The smile that passed between them was not warm. It was far from loving. A cold, manipulative curl of Ciel's lips and a smirk on Sebastian's features that revealed his true nature, that was all.
But perhaps that was their own kind of love.
Because when Sebastian turned to go, Ciel realized something.
He wanted to kiss him.
And perhaps his earlier thought should be amended. The two were bound inextricably together, yes. Sebastian was his to command, body and soul, and one day, the tables would be turned upon him.
But he did not own the demon's heart.
The door closed. In the darkness, Ciel almost laughed.
Almost.