Disclaimers: I do not own. Downton Abbey is Julian Fellowes' baby.

A/N: I finally got to post my multi-chapter S2 AU story that I worked on for a while now.

It's quite long and I shall try to post regularly. There'll be a lot of angst, paired with a lot of fluff and the rating will be appropriate for later chapters, trust me ;)

Now, I feel that I ought to explain a few things beforehand...

First off – Lavinia. You'll find a very, erm, shall we say different Lavinia in this story. Partly because I had no clue what Matthew's fiancée would be like when I started writing, I only knew her name before S2 started. I debated whether I ought to rewrite her, but then, the story would not be what it is now and I admit I had rather too much fun writing her more kick-ass and less meek. Apologies to those who love sweet!Lavinia, I just couldn't bring myself to change her, so she's become one of the AU elements.

Secondly, the war will feature a lot in this, even if we're not initially in the trenches. But the thing is, I always wished that we could have seen more of the effect that the war had on Matthew and others, because it must have, whether JF chooses to show it or not. So we'll also see a rather more afflicted and emotional Matthew in this story. And tbh, seeing the way he fusses in S3 now, it may not be so far off the mark :)

Let me know what you think and reviews would be lovely! Thanks for reading, hope you enjoy!

These Endless Days

I.

"Dearest Mary,

How odd not to be home when the Christmas bustle starts at Downton. And how I miss you and Mama and Papa, Edith and Granny. Of course the hospital work is keeping me occupied and there is lots of company around here. You know Aunt Rosamund keeps inviting those odd acquaintances of hers. The Cartons had been here last week, with their children. Little James smashed a tooth out while jumping up and down the furniture. Aunt R has had about enough of them. Miss Swire wasn't too amused either when Sylvia spilled Mousse au Chocolat on her dress, then smudged the rest onto her little brother's face. Lavinia said: 'When Matthew and I have children, they won't be quite as naughty." Please don't be mad at me, but I simply had to tell them about the time when you and Edith took Papa's ink and painted my face blue with it, so we could play that I had typhoid. Nobody wanted to believe it here. They must think you were a perfect angel when you were a little girl. Please, don't be mad that I told them. On a more interesting note, guess who turned up for a call. Miss Swire just came in to tell me Evelyn Napier has arrived in town. He must be on a stop-by before he comes to Downton. But you probably know that already. I haven't got any more news for you, I'm afraid. We shall go and see 'The Nutcracker' at the Gaiety tomorrow night and I'm rather looking forward to it. How I wish you were here with me. It is so dull with Miss Swire as company. Of course there's Matthew, but he is rather dreary these days. Understandably. How is Edith doing? Tell her I'll write to her next time. Please give my love to her, Mama and Papa and Granny of course. Write to me soon. I miss you terribly.

Your sister,

Sybil Crawley

P.S. Matthew does too, I believe.

S.C."

A cloud of cool breath escaped Mary's parted lips and blurred the frosty window next to her flaming cheek.

"Does too..." she whispered, unbidden images of last spring invading her mind.

A warm April day, on a surprise visit to Cousin Isobel to sneak some news of her son.

Then a shock, Matthew in his officer's uniform, standing awkwardly in the small drawing room. Molesley serving tea, looking uncomfortable.

Then her. Her. Her! Small and slender, flaming red hair, done up in an elaborate hairdo.

And her eyes. Green, piercing, scrutinizing. "I'm Lavinia Swire...Matthew's fiancée" she had introduced herself, as neither Matthew, nor his mother could find their voices.

In Mary's opinion, that was exactly what identified them as middle-class. Aristocrats know how to function even within the most awkward of social hellfires.

Mary had played her role to perfection. Smiling, she shook the offered hand, introduced herself with her full title and exchanged pleasantries that rose in her throat like bile and laid in her stomach like lead.

Even know she didn't know how she had managed to get home in one piece, sneak into the house and up to her bedroom where she had wept so hard and long until the pain dulled and she felt quite numb.

That's how she felt even now, many months after the incident, the thought of Matthew and his engagement always triggered a self-defensive chill inside her, an instant mechanism to shield herself from the painful impact that a broken heart had on her.

With some satisfaction, she noted that Matthew must have had a bit of a shock himself on that day, though Mary never quite understood why or even what right he had to be upset. It must have been the war affecting him and she felt genuinely sorry for it.

She had written to him about Evelyn's proposal a good while ago, and never received a reply.

Of course he had never replied to any of her letters since 1914.

Given that he was happily engaged now, Mary would have thought that he had made his peace with her, that he had let go of all the resentment and pride.

That's what broke them, her stupid hesitation and his idiotic pride.

Or so Mary had thought up until last spring.

Evidently, Matthew can't have loved her so very much, if he found it in his heart now to replace her with the likes of a Miss Swire!

Mary hastily stuffed Sybil's letter back in the envelope, ripping it half to pieces in the process.

No, there was not much love lost between them. And it was all so very irksome.

If she had made an effort to keep it together on that fateful afternoon in April, she would have expected him to do the same.

But there had been no change in his demeanour towards her, rather the contrary.

The loftier and friendlier Mary had acted, pretending to be charmed with Lavinia, pretending to be happy with her own prospects, the darker his moods had become.

Edith, barely able to contain her glee, would tell Mary later: "Do you know, I believe, he's finally grown as sick of your pretensions as the rest of us are."

Mary, barely able to contain her rage, had merely smiled and said: "Perhaps you are right."

She had long learned to reduce her conversation with Edith to polite small talk and disarming bluffs, having decided that she could never again trust her sister with a single emotion or thought, not after Edith's betrayal.

And since messing with Mary's head was one of Edith's favourite sports, she had soon given up on it.

Mary closed her eyes and swallowed hard, her head leaned back against the inside of the vast window. In her mind she was already drafting a response to her sister.

You are mistaken, Sybil, utterly mistaken. He doesn't think about me anymore. He doesn't care.

He is happy without me, as happy as he can be in this dreadful war...

Why would he so much as waste a thought on me, when he's got her now.

Surely, Miss Swire was his perfect counter part, she belonged to his familiar middle-class world after all, and she was sweet and pretty and simple.

Isn't that what all men want in a wife?

Mary stifled a small sob and crumbled the envelope in her hands.

Bitterness was settling over her like a cold shroud.

"Oh there you are! Mama's been looking for you...heavens, why are you crying?"

The curtain had been drawn back with a harsh pull, causing Mary to jump in surprise, too stunned to cover up her tear-stained face.

Edith stared at her sister with an unreadable expression. If it was concern, she hid it better than Mary could hide her tears.

"I'm...tell Mama I'll be there in a little while." She jumped from the widow sill and started for the door, but stopped before exiting.

"I've had a letter from Sybil. She sends her love."

Without a backward glance at Edith, Mary left the room, the letter clutched in her fist.

Edith was left to stare after her, pleased and disturbed in equal measure.