Author's Note:

Rating note: This story is Mature. I first posted this on Archive Of Our Own ( ao3 DOT org /works/1327075/). The original had a few explicit sex scenes which I've toned down substantially/taken offscreen here. Otherwise, it's the same as the original.

Warnings (spoilery): This story gets dark for a bit during HLV. Temporary pregnancy ambivalence; temporary severe depression/suicidal ideation. I promise there's a happy ending.

Acknowledgements: Huge thanks to my beta readers - especially Lisa E., Amy P., ShinySherlock, AxeMeAboutAxinomancy, and never(r)where. I also made extensive use of Ariane DeVere's transcripts of the show ( arianedevere DOT livejournal DOT com / 36505 DOT html) and am deeply indebted to her. See the original copy for more extensive notes and acknowledgements.

A wave of nausea. Fight it off.

Focus. Last chance to find another solution.

Top priorities, incontrovertible: the target must live. John must be protected. Of lesser importance, but not insignificant: personal escape.

No choice, then.

Or, more accurately: there may be another choice, but it would take a Holmes to find it.

Ironic.

Pulling the trigger, a realization: Mycroft is going to kill me.

The bullet hits Sherlock's chest, and he falls backward to the ground.

(Much earlier.)

Her name was Gwen.

Agatha was her grandmother's name and the name her parents called her. She hated it. Adams was her father's name, and the name they called during roll at school. Raya was her other grandmother's name – her mother's mother – but she didn't share that one, usually, because they made funny faces and asked where she was from. (They asked that anyway, if they met her Baba Raya, who lived with them and taught her bread baking and Ukrainian - but hardly anyone ever came over, so hardly anyone ever asked.)

Gwen was the only name that was hers alone, and it was the one she gave her peers and teachers. Everyone called her Gwen except her family.

When she was young, she wanted to be in the movies.

Not an actress - she wanted to be James Bond. Jim Phelps. John Steed.

She had a few friends, but mostly preferred to play on her own, pretending to shoot guns, pilot fast cars, narrowly escape death, and outwit the enemy.

When she was older she realized that spies weren't real. At least not like in the movies, where the world was populated with people running around on secret missions, and anyone might turn out to be an undercover agent at any time. Besides, the British government probably wouldn't trust her, not with her family – in the movies, the Eastern Europeans were always the bad guys. She still wanted to see the world, though, and craved adventure.

At age 11, she decided to be a soldier, ideally an officer. Unsure how to go about this, she enrolled in every possible subject and sport, and worked to excel in them all.

At age 16, she ended up being a nurse. Her mother grew ill. Her father, long gone, sent money but not enough to hire help. Her Baba Raya had passed away several years earlier. Gwen quit her extracurricular activities and focused on little else besides schoolwork and taking care of her mother. Her few friends drifted away. Caring for her mother alone was hard work, but there was a relief in keeping busy, in feeling useful.

When her mother died, there was nobody left, and no money. The next day, she enlisted with the goal of becoming a combat medical technician with the RAMC. She could see the world, experience danger, and if anything ever happened to send her home, nursing skills would make her employable.

She'd just finished her training when the British government showed up on her doorstep and asked if she wanted to be a spy.

"You'll be well compensated, of course," the man in the gray suit told her with a smile that stretched his cheeks but reached nowhere near his eyes. "And have all the excitement you could want, I should think."

"Mm," she said. She tried to appear disinterested, staring at the walls of whatever strange warehouse they were in, but anyone who would get into a black car with tinted windows without asking questions was someone who obviously enjoyed living dangerously.

"You'll want to be aware, however," he continued, leaning on his umbrella, "that we take our oaths very seriously. Should you ever divulge any information about your work, everyone you care about will be at grave risk."

She laughed in his face. "I don't care about anyone." She had, long ago. But the loss of her Baba, father, mother, and friends in turn had convinced her that it was not a useful pattern to continue.

"Good." His smile appeared genuine for a moment. "It will be to our advantage that you lack pressure points. I have been looking for someone with your interests, intelligence, and lack of connections for some time. I have just the mission for you."

"Oh?" She stopped trying not to sound intrigued.

She trained with the CIA before taking the post in Russia (she'd expected MI6, but the man in gray told her it would add another important layer of indirection to have a past in the American service). She learned languages, brushing up on her Slavic and studying a host of others – as well as codes, memory techniques, sharp-shooting, interrogation techniques and how to withstand them, and more. It was exciting, thrilling, everything she wanted.

And then it was dull. Her job in Moscow, following a corrupt government official and tracking his dealings with various unsavory characters, was not all she'd hoped. There was the occasional assassination, but the vast majority of her time was spent listening to mundane conversations and looking through bank records. She grew bored. And she grew tired of scraping by on the meager wages of a part-time nurse - her cover identity.

Finally, she made contact with some unsavory characters herself. She took side jobs, got rid of people. Probably mostly people nobody would miss, but she didn't bother to look into their backgrounds. The pay was good and the risk was high, and it was perfect.

Eventually, she made enough money and started to attract enough attention that it was time to get out. She could retire at 30 and live like an heiress, if she wanted to. Late one night, she disappeared. Left the CIA, left her post, left her life. She took on a new identity so that neither government officials nor unsavory Russians would be able to track her down.

She'd always wanted to live in London as a child. Gwen never had the chance, but Mary would.

(Recently.)

The man in gray looks displeased by the condition of the condemned building where they meet. He obviously isn't much for fieldwork; the room is dim and drafty, but it has a substantially larger number of intact walls and far fewer rats than many regular meeting places she's had in the past.

"You've done well," he tells her. "Just the right signals of disillusionment at just the right time, and quite the trail of assassinations following that. We've covered that trail, but not too thoroughly. Anyone who pokes deeply enough at your past will find traces of your unofficial activities in Russia. Definitely enough for leverage." He smirks a bit at "unofficial," and she returns the smile, as of course it was he that fed her all the targets, via several levels of indirection.

It's been ages since they met in person. She's almost missed him; she's been homesick for England more than a few times, and sad though it may be, this man is the closest thing she has to a friend. Not really very close - she's only just learned his surname - but he is the only person who's known who she is all along. She's glad to see him again.

"So, now that you're sufficiently blackmailable," Mr. Holmes continues, "it's time to send you after the true target."

"Magnussen," she says. He nods.