I've borrowed some dialogue from the show and twisted it a little for this story.

Lying in her bed that night, Mary kept returning to the heart-stopping moment she'd heard Tom's familiar Irish lilt behind her at Carson's wedding breakfast, replaying it over and over in her mind. How she'd spun around thinking she must be imagining things only to see him standing there, Sybbie balanced on his hip, solid and real and here.

And he was staying. For good. Back in Downton where he belonged. Back in the place he never should have left.

The rest of the afternoon had been a blur as it seemed the world and his wife had wanted to welcome Tom back and question him endlessly about why he had abandoned the Great American Dream to return to Yorkshire.

'Well, that's obvious,' Mary heard Mrs Patmore pronounce sagely when Daisy posed just that question as Mary was slipping past them. 'Why wouldn't he want to come back to God's own county? There's no place like it. The lad's not daft.'

'But there's such a big world out there, Mrs Patmore. Wouldn't you want to see a bit of it if you got the chance?' Daisy asked a little wistfully.

'I'm quite happy where I am, thank you. I was born in Yorkshire, I was bred in Yorkshire and, God willing, I'll die in Yorkshire, and I shall be very happy with my lot,' the cook answered her, firmly.

The whole family had given Tom a warm welcome home. Her father, in particular, appeared delighted to have his son-in-law back in the fold, monopolising Tom, shaking his hand and repeatedly clapping him on the back. She'd even seen her grandmother stop to graciously offer Tom her cheek to kiss and tell him in a very un-Granny like way, 'I'm glad you're back', an honour up there with anything the King could dish out.

Isobel, always a great fan and champion of Tom's, seemed almost as thrilled to have him back as if he were her own son. That was a turn of events Mary found both incredibly heart-warming and incredibly uncomfortable.

Between her parents, Edith, Isobel and the new Mrs Carson, not to mention a host of others, including her own very excited son, Mary had been able to do little more than gaze at Tom from across the room, trying very hard not to let the whole world read her feelings on her face.

Anna had beamed at her from her spot by Bates but was discreet enough not to come up to speak to her. Carson had caught her eye, a look of caution on his face. And Mary was sure Mrs Hughes – Mrs Carson – had cast her a benevolent, knowing look.

But as for any conversation with Tom himself, there had simply been no opportunity to exchange more than a few sentences, none of any great consequence beyond a heartfelt, 'I'm so glad you're home,' as her father pressed a drink into Tom's hand.

That night at dinner, Tom was almost grey with exhaustion as he valiantly battled to both stay awake and satisfy everyone's curiosity about his decision to return to Downton. In the end, Cora packed him off to bed, telling everyone they had time enough to interrogate him in the coming days. Mary watched him go, practically asleep on his feet, and decided to leave her personal welcome home until the next day.

So, there she was, lying awake, delighting in the knowledge that he was back under the same roof as her, but rueing the fact that they were not as yet in the same bed, even if only for a few precious hours. Then for a good while, she tossed about trying to get comfortable as she turned over and over in her mind the things she wanted to say to him when she finally got the chance.

After breakfast, during which Edith had irritated her by practically dismissing her work as the agent for the estate, Mary went to the office. She went alone as her father claimed Tom's company again for reasons he didn't share with the rest of them

When Tom finally arrived at the office, Mary felt the butterflies in her stomach take flight at the sight of him. It was a feeling she'd sorely missed over the last few months. She pushed back her chair and went straight to him, slipping her arms around him. 'Welcome home, Tom.'

She could have sworn there was the briefest of hesitations before he hugged her back. 'Thank you. It's good to be back.'

She leaned forward to kiss him, but as she did so, he pulled out of the embrace, turning away so her lips bounced off his cheek. Tom went over to the rack to hang up his hat, without acknowledging the missed kiss. Mary frowned, feeling a little wrong-footed like something was off between them.

'Papa finally let you go then.'

'Yes,' he said, with a small smile. 'Eventually.'

'He's missed you quite badly. Rather more than he expected, I think.'

'That's nice to know.' Tom clasped his hands behind his back, cocking his head to look at her. 'Actually, he wanted to talk to me about something.'

'Oh, yes? What was that?'

'You.'

Mary frowned, apprehension darting through her. 'Me? Why on earth did he want to talk to you about me?'

'He said you'd been doing a sterling job as the agent. He was worried I'd come back and simply take over. He doesn't want me to elbow you aside. He thinks having a purpose is doing you the power of good.'

'Well, that's rather sweet of him, but I'm happy to work with you again, Tom, you must know that. We can be joint agents.'

'That's kind of you, Mary, and I'll think about it. I would like to keep my hand in with the estate, but I've changed since I've been away. I'm back at Downton, but if I'm to live my life out here, I need to have something to do that's not just about the estate. I need something else. I can't go on as I was before.'

Mary felt her stomach clench. 'I see. How enterprising.'

'I've seen American capitalism at work, where a hard-working man can go right to the top, all the way in a single lifetime.'

'Which still isn't true here.'

'Not yet, but I've a sense it's going to change, and in the not-too-distant future. I hope that doesn't worry you.'

The way he was talking, not like the Tom of old, like her Tom, absolutely terrified her, but Mary swallowed her fears. 'Tom, I want what you want. In your work, in your life… although no more Miss Buntings if you have any pity.'

Tom looked askance at her and gave a small, rueful laugh.

Mary felt a knot tighten in her chest, wondering why she'd felt the need to bring up the ghost of the wretched Miss Bunting. 'But even in that,' she continued, feeling like her own worst enemy but unable to stop herself talking, 'don't please us. Please yourself.'

Tom gazed at her, his face closed, unreadable. 'What about you? Have you regretted dismissing your suitors?'

Mary held his gaze, noting that he hadn't said anything about them and what they'd been to each other before he left. 'No.'

He was silent for a moment, that inscrutable look still on his face. 'Right, well, we should probably get down to business. You can tell me what's been going on around here while I've been away.'

'Of course,' Mary said, trying to ignore her heart shattering inside her. Anna was wrong. Tom wasn't secretly in love with her. Not even in the slightest.