Ethel thought about the portrait every day, and the mystery behind it. She added to her notes daily, extending her list of suspects and drawing them into a conspiracy that she liked to imagine had been going on for years. The woman in the portrait couldn't have been any older than thirty, perhaps not even a day over twenty-five, but the picture hadn't been commissioned yesterday. Ethel didn't profess to be a great expert when it came to photography but what she did know was fashion. She'd read enough magazines in her time to date the woman's elaborately beautiful dress back twenty years or so to before the turn of their new century. Twenty years the names on her list, or at least the chief suspects she was convinced were involved, had been embroiled in a conspiracy with the Lady in the portrait at the very centre of it. And every day Ethel was even more determined to uncover the truth.

It was Carson Ethel was most suspicious of at first, and she initially focused most of her efforts on him accordingly. The portrait hung in his pantry after all, in the very centre of the room like a shrine to a lost lover. But that couldn't be it, could it? It was too simple, and what did Carson's former lover – and she had trouble even thinking that with a straight face – have to do with any of the others? Bates she had ruled out early on. He was a secretive sod, no question, but not about this. She'd once dropped the portrait into a conversation with him and Anna – one of the most tedious in her whole bloody life – and neither of them had had a clue. As for Lord Grantham, his generosity had its limits, and Ethel doubted he cared two figs for anything that had happened to his Butler before he had come to Downton Abbey. No, Ethel doubted His Lordship would even know he'd been married before, if indeed he had. And the housekeeper…Well, Sarah O'Brien didn't care about anything but her job and herself. But Ethel's suspicion soon fell back on her.

Of all the people Ethel hated in this wretched place, O'Brien topped the list. She was sharp, she was rude, she was a pain in the bloody backside and rumour had it she wasn't even a real housekeeper. Not only did she neglect to do things the proper way and utilise her customary moniker, but O'Brien had apparently been a lady's maid once upon a time and was therefore completely unsuitable for the position she'd been elevated to; Ethel was sure she'd be a much more suitable housekeeper, if she didn't have other dreams. So then why had O'Brien been elevated? And more importantly, why was she no longer a lady's maid?

She scribbled the question in her little notebook with the rest of her clues, and took her place at the dinner table, sneaking a furtive glance in the so called housekeeper's direction.

She was in her customary place at the table, to Carson's right, focused silently on the task in front of her, a delicate lace shirt she seemed to be mending. Ethel hadn't noticed before but O'Brien was usually occupied with similar tasks. She left the larder to Patmore and the younger maids to Anna, and spent most of her own time sewing buttons on things like she was still a lady's maid and not the housekeeper at all. It was Wormwood's work, she thought, with a glance to the sullen looking lady's maid, not O'Brien's. Her hand itched to reach for her notebook, but something else hit her instead.

She wondered whether she could get away with it – it wasn't a crime after all, to ask questions – but the witch had been on edge lately, like she knew precisely what Ethel was up to and she'd had to be more careful as a result. But this was much too good an opportunity to ignore.

Ethel fixed a smile on her face and looked to the head of the table with all of the respectful innocence she could muster.

"Miss O'Brien, would you be kind enough to answer a question for me?"

O'Brien barely looked up, sparing her little more than a meagre inclination of her head as she pulled the thread through the fabric in her hands.

"If I 'ave to."

The room tittered with laughter but Carson soon shut them up with a simple arch of his brow. It didn't dissuade Ethel though and she maintained the courteous smile.

"I've been thinking about my place, you see, and what I want to do in the future. And I so admire you," O'Brien snorted in disbelief, but Ethel pressed on. "I wanted your advice."

"Keep your 'ead down and don't sleep with the boss."

The reply came so quickly that Ethel found herself momentarily speechless. There was a snicker at the table, but somehow she didn't find it particularly funny. It was an odd little comment, meant as a joke she supposed, but there was an edge to the words that she found curious. She'd note it down later but for now…

"Thank you, Miss O'Brien, but I didn't mean that."

"Get to the point please, Ethel," Carson interjected with his usual crustiness. Ethel fought the urge to toss him a glare, but it would hardly serve her interests if he silenced her completely for the crime of a dirty look. "Miss O'Brien doesn't have all day to answer your questions."

She certainly didn't look that busy to Ethel but she smiled all the same. It was becoming painful to keep up the smile now; her cheeks were starting to ache with the effort of it all, and she resolved to get to the point. Now, and for her own sake if nothing else.

"Of course she doesn't, Mr. Carson."

She turned back to O'Brien. She was still focused on the work in front of her, but she'd soon have her attention. Any minute now, in fact.

"I apologise Miss O'Brien, only I'm not sure which I'd rather be; a housekeeper or a lady's maid."

There. She had the battleaxe's attention, the whole lot of it judging by the stunned look on her face, and she plunged the knife in deeper with a saccharine smile.

"And as you 'ave experience of both, and at this very house too, I couldn't think of anyone better to ask."

This was the most fun she'd ever had in this stupid house. With the whole room suspended in silence, Ethel found herself fully appreciating the rare and wonderful sight of a speechless, maybe even a little frightened, Sarah O'Brien. Oh she was onto something now, she could feel it! That O'Brien had once been a lady's maid here at Downton had something to do with her mystery, she knew it. Even if the previous Countess had died, surely she'd be kept on as a lady's maid? She obviously preferred the job more than she did being the housekeeper. Oh yes, it definitely meant something. And Carson and O'Brien knew it too.

"Were you a lady's maid, Miss O'Brien?" Daisy asked, with all of her usual ignorance. It made this moment even sweeter. "I didn't know you could be both."

"You can't," O'Brien answered in a clipped tone. She began packing up her needlework, but Ethel was hardly going to let her leave now. She had so many more questions to ask, so much more evidence to gather before she let this wonderful moment come to an end. As it turned out, Daisy had no intention of letting her go either.

"Why aren't you a lady's maid anymore? Didn't Her Ladyship like you?"

The housekeeper opened her mouth to answer, but Mrs. Patmore, fresh from the kitchen and out for Daisy's blood beat her to it.

"She wasn't Her Ladyship's maid, you foolish girl, she was the first Lady Grantham's maid. Now get back in this kitchen before I drag you in there myself!"

Daisy made her escape, leaving behind a trail of devastation that had the whole room in silence, and O'Brien…O'Brien looked remarkably like she had been slapped around the face.

Ethel grinned, practically bouncing in her chair and itching to reach for her notebook to write this all down. How had they never known about this before? A divorce would surely have made headlines and maybe it had, but most of the staff were either too young to remember or too tedious to care. Ethel on the other hand lapped it up.

"The first Lady Grantham?"

O'Brien rolled her eyes, but it seemed to Ethel it was taking all the energy she had to appear indifferent. And her eyes told a different story altogether. "Yes."

There was silence for another long minute before Ethel, ignoring the warning in Carson's eyes – this was far too good to let go – asked the question everybody else was dying to.

"And where is she now, Miss O'Brien?"

"Dead."

She stood up abruptly, packing her sewing away with a darker look on her face than Ethel, and perhaps any of them, had ever seen before. For a moment she regretted ever having said anything, but this was progress, this was real progress and her thoughts went back to the woman in the portrait, with her blue eyes and dark hair and the air of majesty that seemed to surround her despite her youth, and it suddenly made sense.

The woman in the picture was the first Countess of Grantham.

But what was she doing hanging in Mr. Carson's pantry?

"Tea is over, everybody back to work."

O'Brien stalked out of the room without another word, and Carson soon followed her with a final, wordless rebuke in Ethel's direction. Despite herself she felt her lips curl into a smirk of triumph. She'd gotten further in ten minutes than she had in weeks of investigation and she'd knocked Sarah O'Brien down a peg or two in the process.

High on success, she left the Servant's Hall to attend to her duties.

Ten minutes later, Ethel walked purposefully past Carson's pantry as she made her way upstairs, hoping for her daily glimpse of the woman she know knew to be a Countess.

It had become routine to seek her out her pretty face, and to revel in the mystery of her for just a moment before she returned to the daily grind of life. It seemed almost a shame to spoil that mystery and expose her for all she might be; for all she knew the Countess had been committed for serial infanticide, but then why would Carson have her hanging in his room? Why would O'Brien care so much, when she cared about nothing else?

And today she was in luck. She wouldn't dare knock and disturb Carson after pushing her luck so much already today, but the door was already open – just a crack, but it was enough to see her, smiling serenely out over the room and across to Ethel like she was greeting a dear friend. She didn't feel like a portrait anymore, not really, and with every new piece of information Ethel stumbled upon she came to life all the more. And she was no longer just an untitled Lady, she was a Countess, a Countess who had been married to Lord Grantham, had lived under this roof and walked the very floors Ethel did every day.

That knowledge made her feel less alone somehow.

But the Countess wasn't all she saw, and, before Carson slid the door shut on the portrait inside, she caught the briefest glimpse of Sarah O'Brien, so brief Ethel wondered if she'd imagined it, with her head in her hands and the ghost of the her former mistress watching over her from between the glittering picture frame.

For a minute, just a minute, Ethel felt inexplicably sorry for her.

And then she retrieved her notebook, and hurried upstairs.