'I hope m'lord don't think it impertinent of me to ask, but is it true Lady Arya's got a wolf?' the gaoler enthusiastically enquired as he led Jaime down to the second level of the dungeons.

'Nobody can truly own a wolf,' Jaime replied distractedly as the world grew darker and narrower around him, 'but yes, she does have one. She's rather large.'

'Lady Arya?' the gaoler asked, confused.

'The wolf,' Jaime growled, exasperated.

'I heard she can kill twenty men without blinking.'

'I've seen her do it. She's especially intolerant of people who talk too much.'

The gaoler fell silent, not asking if he meant Lady Arya or the wolf.

In the week that had passed since their arrival at court, Arya had expressed no opinion on the subject of Cersei's final request. Jaime hadn't either. But on every single one of the seven days that they had broken their fast and sparred in the godswood and attended court and argued and shouted and loved each other, he had seen a flash of coal in Arya's eyes that told him she was thinking of Cersei, even if she would not speak of her. It would begin with a glow of hatred made darker by disdain, then transform itself into the same expression that she wore when thinking of the dead she had never said goodbye to. Every time that look crossed Arya's face, Jaime became surer and surer that he really ought to go; and today, when he had told her of his intentions, she had smiled at him, but said nothing.

The beheading was to take place tomorrow, and though Jaime was no longer afraid of himself, a shadow and a whisper took hold of him with cold fingers and crushed him as the infernal flame of the gaoler's lantern led him deeper and deeper into the harrowing moisture of the darkness beneath the Red Keep. A shadow and a whisper and a certainty: the knowledge that Cersei was his twin; and his blood no matter what she had done, to others or to him.

He did not blame her for the worst of what had been called her crimes. Even now, he thought that any woman with the slightest sense of self-regard or pride would wish to assassinate a husband who treated her with the shameful want of decency and respect that had come to define Robert's marriage to his sister. It enraged him even now; the thought of all those countless hours of guard duty listening to Robert fuck one whore after the other; the smell of wine clinging to him (and them) like a sickness.

But what had Cersei's behaviour to Tommen during the trial been, if not a shameful want of decency and respect; of love? How could she claim to love her son when she was capable of doing that to him?

A gust of wind, from the gods only knew where, came howling out of the gloom to snuff out the gaoler's lantern; and as Jaime listened to the man swearing and searching his pockets for a light, he was suddenly and inexplicably confronted by a vision of Sansa Stark standing at the edge of the Moon Door, telling them of how Lysa Arryn had conspired with Littlefinger to kill Jon Arryn.

Jaime had rejoiced in the old fool's death when it had happened, and he didn't much care about him now. But all the same, he couldn't help but wonder if Cersei had also…

No, he thought firmly, she would have told me.

The lantern burst into flame once more; and as they reached Cersei's cell, the gaoler bowed to him; the keys rattling in the lock as the door was pulled open, and Jaime was allowed to enter the room.

It was large, gloomy, hot and bare; the stone walls streaming with humidity; the stale air smelling of moisture and death. Jaime's eyes took in the table with no chair, the fireplace with no fire, and the simple straw pallet where Cersei sat in full court dress; her green eyes, now red, falling on Jaime and staring at him; her golden hair undressed and cascading down to her waist.

'Get out,' she commanded.

For a moment, he assumed that she was talking to him. Then he saw Cersei's handmaiden; a girl hidden so deeply in the shadows that he hadn't even noticed her. She laid down her work and bolted; knocking rapidly on the door to be let out, and slamming it behind her when her request was granted.

Cersei did not rise to greet him, sitting on her pallet as she might have sat the Iron Throne. She was wearing a gown of very pale blue that only seemed to make her face seem more ghastly, and there were new lines gathering cruelly around her eyes and chin like knife wounds; a woman made old by her own folly.

'Come to say goodbye, sweet brother?' Cersei purred spitefully, 'I believe it's my last night in this world.'

I shouldn't have come, Jaime thought.

'They tell me you've been at court for a week,' Cersei continued, 'I'm surprised you didn't come sooner.'

'You are?' Jaime enquired blandly.

'I am,' Cersei insisted, 'though perhaps I shouldn't have been. You did not answer my raven scroll. In the past, you would have killed the person who treated me with such cruelty and disrespect.'

'I'd just gotten married, Cersei,' Jaime stated, trying hard to keep the indignation from his voice, 'I had better things to do than waste time and effort answering nonsense.'

'Fucking your little Northern whore, were you?' she sneered in reply.

'However I choose to spend my leisure time, I must confess that I didn't think it appropriate to demean the Queen Regent of Westeros by allowing her to name a cripple as her champion,' Jaime observed.

'Perhaps you're right,' Cersei agreed, dismissively tossing her golden head, 'look at you. Wearing that awful stump in a sling around your neck, as though it were a thing you should be proud of.'

'Avert your eyesif you are offended,' he suggested coldly.

Cersei smiled cruelly at him.

'If Father had been alive he would have taken steps to make you hide it long before now. But then Father would never have let Joffrey die, or allowed me to be humiliated in this way, or failed me, as you have.'

'Good thing Father's dead, then,' Jaime smiled back at her, 'and as for Joffrey, well…I couldn't help but notice that King's Landing seems rather caught up in routine for a city that has just lost its beloved ruler. Where is the throng of wailing women outside the Sept of Baelor? Where is the fear in the streets at the prospect of a war of succession? Where are the highborns in mourning garb; the manses draped in black; the two penny portraits at every shop front? You must be proud, to have raised a son capable of making such an impression.'

He expected her to snipe back at him, or to scream, or to throw him out. Instead, she let out a strangled sob and covered her hand with her mouth, and he saw Joffrey in each divided plain of her face as she began to weep; her tears tearing lines in her beauty like ink across a sheet of silvery white parchment; and Jaime felt his anger collapse as pity was born in its place.

In the past, her tears would have made him half-mad with anger, and he would instantly have set out to murder or maim whoever had caused them; knowing that when he returned, her flesh and her cunt and her cries would be his as he wound her golden hair around his hands like rope and fucked her like the hurt and the pain and the torture of what they were; of what they loved to be.

But he didn't love like that anymore, and as she sat there in front of him, weeping for herself and her loneliness and her fear and her child, he was not seized by the slightest desire to charge off into battle against those that she believed had wronged her, or to fuck her into feeling better. She was desperate, and pathetic, and alone…and his sister.

He sat down next to her on the straw pallet and touched her shoulder. It felt like metal beneath his fingertips. She turned to him almost immediately, put both her arms around his neck and pulled him hard against her; sobbing pitifully into his shoulder and shivering despite the heat. In that gesture she took more than he wanted to give, but he did not pull away.

He remembered the first time she had cried like this; when they were children at Casterly Rock, and Jaime had thrown himself from the top of the cliffs; whooping in joy as his body tore through the air and crashed into the waves; and he had looked about for Cersei under the water; expecting her to join him at any moment; to follow him; to do what he had done. He had surfaced to find her staring down at him from the top of the cliffs and weeping uncontrollably; and when he had run up to her and found her again, she had pulled him against her, not caring that he was sopping wet, and he had stood there and held her for a small eternity while she wept, and cried that she had believed him dead. He had thought her fear absurd and ridiculous, but she was his sister, and he had felt deeply, deeply sorry for her, and Father had berated him later for being such an idiot; 'We're Lannisters,' he had said, 'Lannisters don't act like fools.'

Today was the same, apart from one thing. Cersei had acted like a fool this time.

'How is Tommen?' she was weeping, 'how is my little king? Does he hate me?'

'Of course he doesn't hate you,' Jaime replied, her arms around his neck like the bars of a prison.

'Tyrion will find some way to kill him,' Cersei babbled desperately, holding him tighter, her hands hard and cruel, 'I know he will; I see it each time he looks at me, or at my sweet, darling boy; you must protect Tommen, Jaime; promise me, promise me.'

'Tyrion would never seek to harm the boy,' Jaime assured her, with more kindness that he had ever shown her on the subject; 'Tommen is his own blood. He loves him. You may set your mind at rest on that score.'

Cersei shoved him away from her; anger blazing from the redness of her eyes.

'How can I set my mind at rest?' she screeched, hysteria deforming her voice, 'he devoted his life to destroying Joffrey and he will do the same to Tommen; he will stop at nothing until he had seized power! I know it and Father knew it too; it is why he –'

'Don't be ridiculous, Cersei!' Jaime interrupted, fast losing patience, 'Tyrion is the only man who can save these benighted kingdoms from the fucking mess you've made; and he will teach Tommen to be the same, and better. With both Tyrion and Uncle Kevan by his side, your son will be the greatest ruler in half a century – though I'm afraid that's not saying much.'

Cersei's eyes filled with tears, and a sudden hurt so deep it shocked him.

'Our son,' she insisted softly, the whisper hoarse in her throat, 'Tommen is our son.'

Jaime looked at her pointedly.

'No,' he insisted, 'your son. Just as you've so often told me. Do you now claim to regret that?'

'Sweet brother –'

'Don't 'sweet brother' me, Cersei! When he was a baby you wouldn't even let me hold him. It's a little too late – and a little too convenient – to change your mind about it now. The boy is your son, not mine. And the idea of your head ending up at the bottom of a bucket certainly isn't enough to convince me otherwise.'

She slapped him hard across the face.

As Jaime felt his cheek stinging, he saw her eyes flicker upwards to his and her lips part with a sigh that he knew well. Jaime stared bemusedly back at her and down at her hand as it travelled slowly up his leg, coming to rest firmly on his cock.

She did not attempt to kiss him, or undress him. She didn't even try to undo his laces. But her breathing grew heavier; her eyes began to burn with a hard, torturous flame; and suddenly she was staring fixedly, desperately and absolutely at him with the same raw, yearning, near-inhuman gaze that had once been sufficient to drive him half-mad with desire for her. He continued to stare at her, curious.

She started to stroke him; gently at first, then harder when his cock failed to respond. Her confidence was as towering and imperious and lustful as her gaze, and as powerful as her blatant and uncompromising certainty that he would cast everything away from him; cast Arya away from him; and come to her like a dog, as he always had. And suddenly, his bemusement turned to disdain for a master too stupid to realise that she'd reclaimed her slave too late, and disgust at the twenty-five years of his life that he'd wasted.

'You can stop that now, Cersei,' he said, rising, 'at this rate I won't come before I'm eighty.'

'Going so soon?' she drawled, her expression instantly replaced by one of extreme boredom and sound, well-worn spite.

'Your company grows more unbearable by the minute,' Jaime replied.

'You may find it so, brother,' she sneered, 'but I doubt the High Septon will think so when I see him tomorrow morning.'

'Unburdening yourself before you die?' he spat.

Cersei smiled and looked up at him with disconcerting sweetness.

'I've already unburdened myself of a great many sins, sweet brother,' she said, 'they've been flaunted before the realm in all their glorious colour and ugliness. But you, and our children, the best of my crimes – or the worst, now that I know that you have nothing in your veins but milk – you I will spare for last. And the old fool will weep at the purity of my soul before I die, blissfully unaware that no matter what meaningless words he speaks, you and I will be seeing Father soon: in hell.'

Jaime's blood curdled and turned black as he watched her smiling at him; her emerald green eyes; his eyes; dark and alive with the brutal thrill of cruelty.

'You fucking bitch.'

Cersei was still smiling; widely and obscenely.

'We came into this world together, sweet brother,' she said, 'we will leave it the same way. Tomorrow – or not.'