She writes him few letters that year. They are polite, proper, correct. She tells him the major news of the village, the widely-known gossip about the lives of her sisters, expresses honest but overly simplified wishes that he come home safe.

They are open, honest with each other about all but one thing (the most important thing) in person, but for some reason, a letter, which should free her to write as she wishes, without fear of watching the immediate consequences, has the opposite effect. She's more guarded, more careful to conceal. She fills them with platitudes because somehow, she's afraid committing even the tiniest portion of the truth to paper will force her to acknowledge it.

She likes to think she doesn't acknowledge it already. If she's not to have her heart, at least she has her dignity.

So only the most trivial, most predictable of thoughts become etched in ink. The rest swirl in her head, unbidden, stringing together the most absurd of phrases that will never find their way onto the page of a journal, much less a letter to him. She couldn't let them.

Come back to me settles in her throat and in her wrist, the shapes of the letters well-worn and so close it would take but a second to produce them. But she has no claim on him, and so she doesn't, can't, say it.

Missing him produces unlikely dreams. I wish we could argue as we did, just once more.

And, when she feels the weakest, and the bravest, the words speak simplest truth. I love you.

These fragmented thoughts are so much a part of her and of him that she sometimes imagines them etched onto his photograph, faintly visible beside his gaze, when she allows herself to look at it. Only at night, only ever at night, in the darkness, when she prays.

She feels her father read into her soul in these months and find her second most dangerous truth. At first, she thinks his meddling is for the sake of his children—she, and Matthew—a juvenile hope that they could make each other happy once more. And it frustrates her.

Eventually, though, she sees that what he suspects comes from a different place entirely. He loves Matthew, too, He sees through her because he sees through himself, and that binds father and daughter together with fast thread.

A part of her yearns to tell her father, to sob into his shoulder and say that it is no one's fault but her own, that she split them apart irrevocably, that the kinder side of her that hides beneath her cold exterior, which he brought out from hiding, may well be gone forever.

But she is Mary, and all she has is her dignity. She clings to it.

She had once thought love very foolish indeed, an idle, ephemeral pursuit of the outwardly weak. Until she realized that what she wants, what she has always wanted, is to love. She had not learned that with Patrick. She'd been putting off marriage, the decision, without truly knowing her reason. And now she does.

She found it when he came along, when she discovered that she felt no resistance at the idea of being married to a country solicitor, so long as he made her smile when she felt bitter and met her biting sarcasm with equal wit of his own. So long as he gawked endearingly when she surprised him and gave her a look of teasing reproach when he secretly found her amusing.

Love is foolish, in a way. But not in the way which she once thought. Love is all-consuming, all-encompassing. Not because the world has changed or because Mary herself has changed, though she has, but because it defines how she is, who she is. The act, the reality of loving him changes how she reacts to the world around her, even if he does not feel the same.

Her reaction to Lavinia should surprise her. She'd expected to be kind, politely welcoming, and nothing more. But as she begins to respect, even have a fondness for the girl, she feels it isn't strange at all. She wonders at first if it's the same thing that binds her to her father. They both love him, and if Lavinia is what he wants, she'll learn to accept it.

Later, she realizes that that is only the smallest part of it. She wants his happiness, more than her own—and maybe that's what love is.

It has made her feel generous, selfless, in a twisted way, because she wants him to be happy as much for her as for him. Of course she likes Lavinia—she makes him happy; she's a lovely girl. If his happiness means accepting and welcoming her and taking his rejection with grace, then so be it.

So loving him has made her a better person. Strange, how that doesn't make anything hurt less.

That night, when he asks her to dance, she isn't sure what she means by referencing their past. She shouldn't be allowing him to do this, to apologize to her and say however much I might want to and hold her so tenderly, she can't yet decipher what this will mean for them, and yet she can't bear to stop him.

It turns out that what it will mean for them is a matter taken entirely out of her hands.

When everything changes once more, when she sees and hears him wracked with guilt, she begins, "Oh, Matthew..." and she wants to say you always make everything so black and white. Deep down, she knows that's just how things are for him, even though they never seem to be between them.

What he seems to want after a time is for them to be friends. Some things are black and white again—he never could despise her. But where their relationship is remains an abstract shade of gray that neither of them can push to one end of the spectrum.

He is still better than anyone at pulling her out of her shell, they are still open and honest about everything but that one thing, and together, through everything—Mr. Swire, Bates, Christmas, the hunt, they hold their family together.

The day he looks at her and tells her she'll always have a home at Downton, as long as he's alive, she at first feels keenly the difference in who they are and who they were. He's settled as the heir; she's happy, proud even, to have him there. His gaze—there is uncertainty, conflict, but also love for her, she's sure of it, and she aches that he won't accept it. He adds a comment about them being broken, but all she can think is that he's acknowledged that they had something now, to begin with, and that he knows she really loved (loves) him. It's calming to know that he finally (too late!) believes her, but utterly confusing at the same time.

There's a cruel justice about it. She wouldn't have him and now he won't have her. If only one of them was a bit less stubborn.

But then, if he was, she wouldn't love him so utterly. She suspects he wouldn't have loved her.

When she tells Anna not to give up hope, she thinks, inexplicably, of Matthew's eyes in the garden so many years ago, as he choked out a plea for her to love him enough to send the rest of her life with him. What she wouldn't give for the chance.

She and Anna have bonded even more strongly, these past few years, over lost love. Once Carlisle is gone, her own cruelty towards Anna and Carson only adds to her conviction that he brought out the worst in her. She remembers what Anna said about second best, and she agrees.

As she watches Anna find hope again in her husband's redemption, she lets herself hope. For once, since the future she'd imagined at Sybil's ball so many years ago, such a fleeting moment, she creates another. She lets herself dream.

She pulls out real ink and paper, and she writes.

Dear Matthew,

I told someone once, years ago, that I could never build a relationship with you on lies. "That's not how we are together," I'd said, as if by decreeing it to be so, I could make it true, forever. Perhaps it might've worked, had things been different. But then so many things might've been different.

You know that people think I'm cold and careful and unfeeling. You were never one of them, but Matthew, that was your worst, most wonderful, most dizzying mistake.

Because I feel, Matthew. I feel very much, but I'm afraid I do so very poorly.

I cannot distinguish between what my heart wants and my mind corrects, between love and friendship and comfort and duty, between things that will always be there for me to reach for and things that I must hold close in the moment. Between things that must be kept to oneself and things that must be told, even if they are not forgiven.

I've told you now. It would be easy for me to say that it is all that kept us apart before, but that lie between us would suit me no better than that which it would replace. The truth is that I do not know for sure what is was that kept me from answering you. Insecurity, perhaps, about choosing how I felt. Fear that what we truly felt was relief in the fulfillment of a duty to our family. A need for some dramatic moment which made me sure I loved you. Those things seem so silly now.

I hated you, for a few moments on that August day. I hated that I had ruined my happiness and yours and yet you could look at me with such kindness, not even as though you'd forgiven me, but as though there was nothing to forgive. I hated that you could be so sure you would've stayed for me.

In the end, I loved you all the more for it. You were the first person who encouraged my better side without demanding it, who accepted my choices as my right to make, even if you didn't agree with them. Even if they hurt you.

I honestly can't remember a time when loving you wasn't simply a part of who I am. Anna calls it a sickness. Perhaps she's right. Perhaps there is a better metaphor. London fog. Ever-present, not easily ignored, frequently brushed aside, but never forgotten.

I feel that we are at a precipice now. A cliff overlooking the sea. I believe you feel it, too. We have banished the sea monster, the princess's father will manage with his problems, and now it is time for the end of the story. Or will it be the beginning of a new one?

Just when my life looks gray, Matthew, you bring back the color, and the fire. If your judgment requires that you know more about the sea monster and the princess in question, you do. You know Perseus, as well, and I believe he's rather more fitting.

If we are always honest about everything else, let me for once be open about something I believe we've both known for a while.

I love you.

If I spend too much time at the Servant's Ball tonight talking of my plans for America, you must promise me once more to pay no attention to the things I say.

Yours,

Mary

She slips out of her room that afternoon, the letter sealed, and entreats Carson with a kiss on the cheek to have it find its way to Crawley House after the ball has started.

When Matthew returns late that night, an unrelenting smile on his face, unable to sleep, he finds the letter sitting inconspicuously on his desk. He knows who it must be from immediately, and surmises that she sent it before…before, and so is very curious to see what it contains.

When he has read it through, parts of it several times over, some confessions do ache. The last one warms his already burning heart and overrides the rest. He finds a pen and piece of paper, thinks for a moment, and scrawls a response.

When Anna comes to find Lady Mary the next morning, she hands her the note with an understanding smile. Mary takes it curiously, recognizes the handwriting, and can't stop smiling as she reads the twelve short words over and over again.

What you say matters a very great deal.

I love you.

Matthew