"Come, Athos. Surely we don't have to persuade you to join us for a drink?"

The words jerked Athos out of his reverie. He had been standing on the outskirts of the musketeers' courtyard, studying the world through the stone archway without really seeing it at all. His mind's eye was focused on another stone arch and what had transpired there only hours ago, though it already felt like years. He felt like a different man from the one who had last left this garrison.

As he went to join his friends at the table, he found that this new man walked with lighter steps. It was the absence of her locket, he knew. It had been such a little thing, and yet its weight had been dragging him to the ground for five years. And now it was gone, along with all he had felt for her.

And these men, the three men seated around the table by the stairs, remained. They were the future, and they were all that he needed to move on from the past. He accepted the cup Aramis was offering him, and let D'Artagnan fill it with a generous measure of wine. Porthos shifted over to make room for Athos to sit beside him, but he stayed standing. Every sensation felt strangely new, and when he drank Athos felt like he was really tasting the wine for the first time in years.

When his cup was half empty, Athos paused. He could feel the change that was happening in him, and he felt as though the cool evening wind was, layer by layer, stripping away something that had tainted him for a long time. These men, his brothers, had helped change his world. Today they had fought, they had risked everything, and they had won.

"One for all," he said, and raised his cup towards them.

He had meant to say it with his usual wry humour, but the words came out with a solemnity that he had not anticipated, but that he realised the moment deserved. And with friendship, too, of a depth he had not expressed before. They had shown what they were made of today.

And he could not regret that vulnerability when each of the others met his eyes. Aramis gave him the fond, understanding smile of one who had seen him at his best and his worst. Porthos, the loyal look of a man who had never needed to question him to follow him. And D'Artagnan – D'Artagnan looked like he had finally found home.

"And all for one," they said together, and the four cups met over the table. As they drank, the warmth that spread through Athos was from far more than the wine, and he sat at last beside Porthos feeling more at peace than he could remember.

They sat in silence for a while after that, as the garrison slowly emptied out around them. Their comrades called out farewells to them, or congratulations on what they had survived that day, but none approached. This night was for the four of them, and they remained as the other men departed for their beds, until at last the yard was deserted and lit only by the dim, flickering light of the candles within the musketeers' rooms.

"You know, it's strange, really." Porthos broke the quiet, his voice low and thoughtful. "Milady thought she knew us so well. She thought she was playing us perfectly."

"Not so well as she thought, clearly," D'Artagnan replied grimly, thinking of the time he had spent with her as they carried out their plan. How she had kissed the man she thought had murdered her husband.

"Yeah, that's the thing," Porthos said, shaking his head. "She watched us. She tried to play us. And she thought she knew how to kill us. But our plan never should have worked."

The same thought had been burgeoning in Athos' mind, too. Not an unease, exactly, but a growing awareness that they had somehow snuck a victory that should not have been possible. And yet the idea was only half-formed and he could not find the words for it – so he pressed Porthos, instead.

"What do you mean?"

Porthos studied the wine left at the bottom of his cup, and did not look round at them as he continued. "If you had died, Athos – if any of us had really died... The rest of us would not be found sitting around in a tavern. We wouldn't even have been at the funeral. Because we wouldn't be stopping, we'd not be resting. If it were any one of you, I'd be tearing the world apart."

And that was it. The plan had worked because Milady had believed Athos was dead, but if she had known them at all the farce would have been utterly clear. If she had really understood how much they meant to each other, she would have seen the trickery behind the carefully feigned grief. She would have known that no force but their own death could have kept one man from avenging another.

Athos feared for them, sometimes. One for all and all for one – it was more fragile than any of them admitted, because if you removed one then the rest were lost.

They had all lost people before. In the half-light he looked round at them, and could see the pain in all their faces. D'Artagnan had lost his father. He had never spoken of his mother and yet he had never looked back towards his old home after coming to Paris, so it was clear that nothing waited for him there. Porthos had lost a mother he'd barely known and in his youth death had lurked around the corner for every friend he made, as Charon had so recently shown. The shadows of Savoy never quite left Aramis, waiting in his dreams or in the first snowfall of winter. And for Athos there had been Thomas, the brother he should have protected, and who had been lost through his failure.

They endured. The pain of those ghosts had not destroyed them, nor would it ever. But the thought of losing these three men was something worse, something darker. They survived all they had lost before because they had each other, and Athos was not sure what their loss would do to him. What would remain of him without them.

He knew he needed to say something. He was their leader, and it was his past that had driven the events of the day, his demon that had threatened them. And yet words clogged in his throat as they always did, the need to reassure his friends tangled up in his own fears. How could he reassure them against uncertainties he shared?

"It scares me."

It was Aramis who spoke, with the quiet air of confession. He leant forward as he spoke and the gold cross hung in the air and reflected the distant candlelight – for Athos, it was another reminder of lingering danger and the risk of loss.

"Porthos is right. That's how I would be, too. And I am scared of that."

None of them had ever spoken like this before. The others barely breathed as they listened, as though any sound would disturb their friend.

"But I will not let that fear rule my life," Aramis said, and though he still spoke quietly his voice felt somehow stronger. "I will not live simply fearing what I will one day lose. Whatever time we have, I would live it completely, so that when the end comes I will know we had something that was worth the sorrow and the pain. I would make every moment worth remembering, not fill them with the anticipation of regret."

They were such simple words, and yet Athos felt like they were suddenly holding up a barricade against his doubts. Before he could find his voice, though, D'Artagnan was the next to speak.

"We are fighters," he said, and there was not a trace of doubt on his face. "I don't know how long a life like this can last, but I know I'd fight to defend it with all I have. I'd fight for any one of you."

He was young, and had known such grief already, and yet his determination was simple and absolute. Because it did not need to be complicated, Athos could see that plainly. To the lad, it was as clear as that – they were his friends, and he would die for them.

And it was that simple. Despite everything else, that was the fact that bound them together. That willingness to lay down your life for a friend. To know that there was something you valued more than your own life.

"It won't stop me, either," Porthos said fiercely. "There's time enough for regret and grief when there's nothing more to be done. While we live, nothing stops us."

All that mattered, right now, was that they were here. Maybe one day, they wouldn't be. It would still haunt Athos at night, the idea that the day might come that he would be the only one sitting at this table. It was such a fragile life because death lurked at every corner, but that was the life they had chosen and it was their duty that had brought them together. It was who they were. And they were right. Now that he had lost the guilt that had held him for so long, he would not let fear consume him in its place.

One day they would lose. One day. But today, they had won. And he would make sure that they won tomorrow, too.

That was who he was. They were his strength, his determination, his courage. They were his weakness, too, but then he would be their strength. He would always get them through tomorrow, and that was enough.

"It is the only life I would have." The thought slipped from his mouth, and the others turned to him. He had not meant to say it aloud, but faced with his three friends he found that the words were not so hard to find, after all.

"I once had the life I thought I wanted. I thought its loss would destroy me. But if that had never happened, I would never have come here. And that alone I cannot bear. Gentlemen, for all its risks, I would not trade this life for any other."

And that was the truth of it; that was all that mattered. They had all chosen this, and from the way they looked at him he knew that for all it had cost and all it would cost none of them would ever walk away.

That is why, growing stronger than the darkness in his soul, there is also hope. Together, they are strong. They will fight for each other, they will defend each other, and nothing but death can stop them.

And besides, Athos thought, what was it that he had heard said of them? He smiled, and spoke the words aloud.

"Musketeers don't die easily."

And as his friends laughed and clapped him on the back, and as mirth filled the void that darkness had threatened him with, Athos knew that he would not be ruled by fear.

He and his brothers would fight for many a day yet.