Author's Note: Just a heads-up…this one is Mary-centric and Mary-sympathetic, so if you don't like Mary, you might want to give this one a miss.

The funny thing is, though I like Amanda Abbington and felt she played the part well, I'm not a huge fan of BBC Sherlock's interpretation of Mary Morstan myself. Thus, I was surprised when this idea came to me over a year ago – and even more surprised when it refused to leave. Maybe it's because, like Sherlock, I really wanted to like Mary – call me a hopeless romantic, but knowing John's marriage would likely, if it followed canon, be fairly brief and end tragically, I wanted him to have happy memories to look back on.

Rather than a chaptered story, this will be a series of canon-compliant one-shots – each based on one of the deductions Sherlock made about Mary on the night he met her in "The Empty Hearse," and all geared towards understanding the character and what motivated her. I don't know if I'll write one for all of Sherlock's deductions, but I imagine I'll add to this collection in between working on other writing projects.

Chapter 1. Cat Lover

John stuck his head around the doorjamb of the nursery. "It's nearly 7:30, Mary. Feel like wrapping it up, maybe having some dinner?"

From her spot in the middle of the sheet-covered floor, Mary turned to look at him with a smile. "Only if your roasted vegetable risotto is on the menu."

John smiled back. "I think that can be arranged. Are you close to a good stopping point?"

"You tell me." Moving carefully in deference to her pregnant body, Mary stepped back into the middle of the room and gestured at the wall with her paintbrush. "What do you think?"

Stepping all the way into the new nursery, John studied the colorful, five-foot high animal she had painted on the wall. He looked a bit puzzled. "That's…nice. That's, er, good. Yeah. Very nice." He glanced uncertainly at her. "It's a…camel?"

Mary frowned. "It's a giraffe. Look at the spots!"

"Of course, yes. I see it now. A giraffe, obviously." Squinting in the glaring light of the naked overhead bulb, John peered again at the painted giraffe (which, in addition to the spots, did have rather a humped back). "The baby will love it," he added doubtfully.

Mary sighed. She could speak four different languages fluently and get by in three more, field strip an M16 in pitch-dark conditions in under thirty seconds, hit the vein on the first try when drawing blood from a patient, and bake a loaf of honey whole wheat bread that made everyone within range of its heavenly aroma begin salivating, but apparently she was utter rubbish when it came to painting cartoonish animals on nursery walls.

Perhaps John's right and we should just do the bird stencils, after all.

John slipped an arm around her shoulders. "It's fine, love. Honestly."

"Love." He called me "love."

Perhaps it was because her hormones had her emotions very close to the surface these days, but her throat tightened, and she couldn't answer or even look at him for fear of bursting into tears. That word was not cheap with John Watson; she could count on one hand how many times he had actually said "I love you" to her, and he hadn't said it at all since he'd moved back into their home after that whole awful business with Magnussen…and Sherlock.

To hide how moved she was, she cleared her throat and asked instead, "How's that cot coming along?"

John made a face. "I've had an easer time patching together shrapnel-riddled bodies than assembling that bloody thing," he admitted ruefully. "I'm not sure who they got to write the directions, but it can't have been anyone who actually tried putting one together…I think I've got it now, but maybe you'd like to have a look at it yourself later."

Before she could respond, she felt something soft brush against her leg, followed by a light tap on her thigh. Looking down she saw Sadie, her small black-and-white cat, standing on her hind legs and bracing herself against Mary's leg with her right forepaw while reaching up to pat as high as she could reach with her left.

"Precious!" Mary cooed. She started to reach down, but John stopped her.

"No, don't bend." Leaning over himself, he scooped the cat up and deposited her into Mary's arms. "There you go." He smiled a little as Sadie, purring, rubbed her nose on the underside of Mary's chin. They both agreed that Sadie had the loudest purr of any cat either of them had ever heard; John grumbled it could be positively disruptive when they were watching telly.

John did not dislike cats, but he was more of a dog person himself. (He had a particular soft spot for bulldogs, which Mary thought were awful). He liked Sadie, though (a good thing, since Mary's pregnancy had, by necessity, relegated him to litter pan duty.) To Mary's relief, Sadie liked John, too. Despite her funny, outgoing, and engaging personality, the little cat had not liked David, which Mary had chalked up to Sadie having had Mary all to herself for so long before David came along. But perhaps not, for the small cat had taken to John straight away. She would always be Mary's cat, but something about John pleased her.

Mary was glad. She only hoped Sadie would take to the baby, as well.

Giving Sadie's ears an absent-minded scratch, John glanced at the darkened window. "Have you looked out? I think we may have had an inch already."

"Not yet," Mary replied, stepping over to the window. She peered through the pane – in the pale light from the lamppost she could see the road and pavement coated with a light, fluffy white blanket, while more snow drifted thickly down. The street was unusually quiet in the wake of the predicted snowfall. "I'm glad we don't need to go anywhere."

"Me too." Surprising her with a quick kiss on the back of her neck, John gave her shoulders a brief squeeze from behind, then left the room abruptly. "You wash up – I'll get dinner started," he called over his shoulder as he disappeared along the hall.

Mary smiled tenderly; John had been very solicitous of her since he'd moved back in just after Christmas, as though making up for lost time. Giving Sadie a quick kiss on the top of her soft head, she carefully set the cat down and began gathering up her paint materials.

They had left preparing the nursery a bit late – she was only six weeks out from her due date – but she had not had the heart for working on it during the endless weeks of their estrangement, when John had been staying at Baker Street with Sherlock and she had mostly been on her own. It was now ten days since Sherlock's aborted exile; the nameless threat behind Moriarty's video was, as yet, still nameless, and their lives were in a holding pattern. Working on the nursery gave John and Mary something to focus on while they waited for what came next – and gave them a chance to get to know one another again, as well.

It hadn't been easy. They had been so uncertain of one another at first that they were like two strangers sharing the house, painfully polite to each another as well as wary. John was a bit distant, and had periods of laconic moodiness. Mary was guiltily defensive, and fearful of being rejected. But assembling the nursery together, with the promise of the future that simple act symbolized, had, along with Sherlock's sudden flurry of cases, done much to ease the tension and divert their minds from the late Moriarty's looming threat. This predicted snow promised to have them both homebound for the weekend, so Mary was glad that things had improved…she was looking forward to a peaceful, cozy time with no interruptions.

As long as the baby didn't decide to arrive early and Sherlock didn't burst in with news of the case (or any case), she didn't see what could possibly happen to prevent that.

Half an hour later, having changed her paint-stained clothes and washed up, she joined John in the kitchen. He already had a pan simmering on the stove and was slicing vegetables on a cutting board on the worktop.

"Mmm, smells lovely."

John glanced up, then paused. His quick smile faded as he looked past her. "What's wrong with Sadie then?"

Mary turned. Sadie, who had been following after her as usual, was now lying on her side in the kitchen doorway with her head up. At first glance she seemed fine to Mary, even if it was an odd spot for her to lie down.

"What do you mean?"

John laid the knife down slowly. "Her hind legs sort of…sank down under her, quite suddenly."

Mary's brow furrowed. There was a funny niggling feeling in the pit of her stomach. "She looks all right to me."

Only now that Mary looked closer, she didn't – Sadie was quiet and still, her head still up as though she were just lounging on her side as cats do, but she wasn't purring (unusual) or watching them with unfailing interest (even more unusual). Her gaze seemed to be turned inward in a rather preoccupied way.

A creeping sense of foreboding stole over Mary, like a spider crawling up the back of her neck. Before John could stop her, she hunkered down carefully, mindful of her rounded belly, and extended her fingers towards the cat, rubbing the tips together.

"Psh-psh-psh! Come, Sadie!"

The cat didn't move. She didn't look at Mary, either. She seemed as consternated by this development as Mary and John.

Mary swallowed. "I'm ringing the vet's."

"It's after hours, Mary." John, having turned the gas off under the pan and put a lid over it, was beside her. He took her elbow and helped her to her feet, then reached down and carefully scooped the cat up. Sadie held herself stiffly in his arms. "They probably closed early anyway, because of the snow. Let's just settle her in her basket and keep an eye on her. Tomorrow we can–"

"I'm calling now," Mary interrupted him sharply, reaching for her mobile.

John was right, of course – the vet's was shut up for the weekend, but there was a message with a number for an emergency veterinary surgery that was open twenty-four hours. To Mary's enormous relief, the snow hadn't caused them to close.

The intake nurse listened as Mary described Sadie's symptoms. Then, after a short but noticeably pregnant pause, she said, "You'll want to bring her in right away." She gave Mary directions to a location a few miles away.

Mary rang off. "They want us to bring her in."

John was aghast. "Mary, it's near-whiteout conditions out there."

"I'll take her. You can stay home if you like."

He sighed. "I'll take her. You'd better stay here and–"

"I'm coming." Her tone left no room for argument.

The events of that dreadful evening remained blurry in her mind afterwards, but a few stood out: the harrowing drive through the heavy, wet snow, with her in the backseat trying to soothe Sadie in her carrier while John cautiously inched along in the lowest gear, unable to keep from sliding a bit through every curve. The staff at the veterinary's hurrying out to meet them and snatching Sadie away to an examination room. The worried look on the intake nurse's face as she took in Mary's condition while she settled John with some paperwork to fill out and gave Mary a cup of tea. And then the vet himself, sympathetic but blunt while explaining his diagnosis and giving them his recommendation: "…kindest thing, truly, Mrs. Watson…she'd thank you for it, believe me…"

They let Mary hold her while they administered the injection. John held them both while Mary whispered into the little cat's ear as the sedative took hold.

It was over in seconds.

She wept bitterly all the way home.

Forced to maintain a snail's pace in the heavy downfall, John did not dare to take his eyes from the road or his hands from the wheel while the car was in motion. During brief stops, he would shoot her a concerned look from the corner of his eye and let go the steering wheel with one hand just long enough to give whatever part of her he could reach a brief, awkward pat before carefully reapplying pressure to the accelerator.

He had never seen her in such a state, and under different circumstances she might have found his alarmed expression sweetly, comically endearing. Probably he thought her surging hormones, combined with the stress, fear and tension of the past months, were exacerbating her distress.

She wondered what he would think if she were to tell him that, if she hadn't decided to adopt a stray cat, they probably wouldn't be married, or fast approaching the birth of their child. Would he be grateful to the little cat, or would he think it crossing her path had ultimately spelled bad luck for him?

Three years before she met John Watson, Mary returned to her block of flats one night after work to find a starving cat half-in, half-out of the rubbish bin at the side of the building.

She knew this cat by sight. The people upstairs had owned it – Mary had seen it sunning itself in their window. It was a small, dainty, black-and-white female with a harlequin-patterned body, box-shaped little face, and rather long tail. When it heard Mary coming, it dropped to the icy pavement and skittered behind the bin, pausing to peer out with huge, cautious green eyes. When she paused without coming closer, it gave a plaintive, hopeful mew, having evidently caught a whiff of the of the sausage roll she had picked up at Greggs.

Mary stared at it. Her neighbors upstairs had moved away ten days ago. They must have deliberately left the cat behind.

Not my problem.

But for some reason, her legs seemed frozen in place.

She had been living in London for over a year, working at the surgery for eight months. At that time her co-workers, if asked, would have described her as "highly competent, but stand-offish and a bit of a bitch."

That was all right. Mary (as she was now calling herself) had no intention of cultivating anything other than the most professional of working relationships. She had come to this country seeking refuge – not connections. She knew from bitter experience that to form attachments was to become vulnerable. Her entire present was a lie, and though she was very, very good at lying, close relationships meant more ways to draw attention, more opportunities for slipping up, more situations in which she needed to keep track of all the tales she had to spin in order to protect herself.

Besides…she was dangerous. She hurt people. She was brilliant and skilled and attractive and people were drawn to her. But she was a flaming torch that would burn anyone who got too close, whether she meant to or not.

It was better for herself and everyone around her that she be alone.

A damp, raw wind cut across her cheek like a knife. Shivering, Mary drew her coat more tightly round herself as she studied the small cat. Her feet were killing her from being on them all day, and her facial muscles ached from constant, forced smiling at recalcitrant patients. She wanted nothing more than to go upstairs, make a pot of tea, and put her feet up for a bit.

Instead, she hunkered down on the pavement, shifted the paper bakery bag to her left arm, and extended her right in a coaxing manner.

The lonely, hungry little thing didn't wait to be asked twice. It trotted to her eagerly, mewing as it came, and circled round her with its tail up, purring happily. After a moment's hesitation, she picked it up. Immediately it rubbed its forehead against her chin, eyes closed in apparent bliss. It seemed even hungrier for attention than it was for food.

She could have snapped its neck like a twig before it even knew what happened – she knew just how to do it. Its easy trust made her throat close up.

It didn't struggle at all when she tucked it inside her coat and carried it up to her small flat. There, she gave it some water and part of her sausage roll. Then she set up a litter pan for it in the bathroom, and spread an old blanket over the end of the sofa. She did not object, however, when, a few hours later, the cat rejected the latter and settled itself on the on the foot of her bed instead.

As its ridiculously loud purr soothed her to sleep, Mary promised herself half-heartedly that she would find a new home for it as quickly as possible.

By the end of the week the cat was wearing a collar with an identification tag that read: "My name is Sadie. If found, please call Mary M.," followed by Mary's phone number.

It was that hopeful mew that had lured her in. The sound was so lonely – and it made Mary aware, perhaps for the first time in her adult life, that she herself was supremely lonely. After spending her misguided youth walking a knife's edge, she had come to this city exhausted in mind, body and spirit. What had once seemed exciting and adventurous now felt burdensome, plaguing, and wasteful. She was in her thirties, but she already had an ocean's worth of blood on her hands and a small fortune on her head. All she had wanted was to rest, and she had never imagined a time when that wouldn't be enough. She had never guessed her life would begin to feel so empty, so soon.

The cat was lonely. Mary was lonely. She could not form relationships with other people, but surely there was no harm in forming one with a single, good-natured, harmless little cat?

One morning, almost a year after Sadie had come to live with her, Mary arrived at work in a supremely radiant mood. It was an exceptionally beautiful autumn morning, the sun was shining, the queue at her favorite coffee shop had been short, and they had even had some of the lemon tarts left that she loved so much.

"Good morning, Mary," the pretty young receptionist greeted her dutifully as Mary breezed past.

"Good morning, Imogen," Mary replied cheerfully with a huge smile. "Lovely day, isn't it?"

She did not pause on her way into the main office. If she had, she would have seen Imogen's jaw drop.

Imagine…that cold, unfriendly Mary Morstan had actually returned her morning greeting with something other than a curt nod. She had actually smiled at her – she had even addressed Imogen by her name!

Imogen couldn't wait to tell Cath.

The cat had begun to soften her.

Without noticing it happening, Mary grew used to hearing, and even to enjoy, the sound of her own voice in casual conversation, for she found herself talking to Sadie more and more when she was at home. Sadie gave her something to hold, scold, cuddle, and cajole. Sadie was always happy to see her. She would call down from the window when she saw Mary coming up the street, greet Mary at the door, and lie in her lap while she watched telly. Sadie would cadge for treats off Mary's plate and sit on the vanity, purring, while Mary got ready for work in the morning.

Perched on the foot of Mary's bed, Sadie kept the nightmares at bay. With the improved sleep, the depression Mary hadn't realized was consuming her began to relax its choking grip. The small flat no longer seemed so cold, lonely and empty…Mary began to look forward to coming home. She loved having someone to come home to – someone who depended on her and trusted her utterly.

Sadie was never horrified when Mary whispered tales of her past life into her ear in the middle of the night. She only purred as she listened, and occasionally nudged Mary's hand reassuringly.

Now, years later, she and John were in bed – but there was no little cat curled up at their feet.

Mary waited until she heard John's breathing change before she opened her eyes. He had drifted off with his arm thrown comfortingly over her, but, ever the soldier, he preferred to face the door, and when he unconsciously turned over in his sleep she turned with him so that she ended lying on her side, facing his back.

Keeping her own breath light so she could gauge his, she waited until she was sure he was deeply asleep before she reached out towards him, carefully and lightly pressing her hands to his shoulder blades. He was a restless sleeper – particularly when distressed in mind – and her touch must be feather-light lest she wake him.

Her caution paid off – he never stirred.

With a soft sigh, she closed her eyes and arched her neck until her forehead rested against the nape of his neck. As always, his comforting scent relaxed her – her heartbeat slowed and her hitching breath evened out. Within her, the baby, having been agitated by her mother's earlier distress, now began to settle as though she, too, found solace in her father's nearness.

Mary had pretended to fall asleep herself, knowing John would not allow himself to do so while she was awake and tearful. But she wanted him to sleep so that she could be free to rejoice in his solid strength beside her in a way she was too shy to do when he was awake and aware, unwilling to overwhelm him with the intensity of her love.

She breathed deeply, slowly, filling herself down to her toes with his wonderful, reassuring scent…a clean, masculine concoction made up of disinfectant soap from the surgery, a hint of aftershave, laundry detergent from his t-shirt, a touch of gun oil, and his own warm skin.

John always wore a t-shirt to bed – long-sleeved in the cooler months, short-sleeved in the warmer ones, declaring jokingly that his internal thermostat had never quite readjusted to England's temperate climate after his years in the Middle East. Mary knew he also was a little shy even now of the scars that marred the otherwise smooth skin of his shoulder. Carefully splaying the fingers of her left hand over his scapula, she could feel beneath the fabric the ridges marking where the entry wound had been.

She remembered the first time she had seen his scars. He had paused while removing his vest, hesitating, then said, slowly, "It's not…well, it's not pretty." Flushing slightly, he had tried to cover his embarrassment by making a joke. "Some scars are sexy, I suppose, but just my luck, this one's butters–"

He broke off when she leaned in and gently pulled the shirt away from him. His breath caught when she pressed her lips to the gnarled flesh over his collarbone, and he flinched and closed his eyes. His muscles quivered slightly – she could feel him forcing himself to hold still, to not to give in to his instinct to withdraw and hide his vulnerability. She could sense his churning emotions, the way he was willing himself to trust her. He was like some wild creature, wary of approach, but it wasn't physical pain that caused him to recoil – she doubted there was any sensation left in the ruined skin; he might not have been aware of her feather-light touch at all had he not seen her do it.

She understood better than he that the scars on his body were, for him, symbolic of the scars on his heart – a heart that had been betrayed and wounded too many times, leaving its owner reluctant to expose it. The thought of his deep suffering – the emotional and the physical, represented in his marred flesh – made her eyes fill and her heart twist with fear…and guilt. She was betraying him right now, and were he to find out he would be hurt again, grievously. Blinking back her tears, she had raised her lips to his, vowing silently that she would never hurt him – she needed him too much.

But of course she did hurt him, and she knew herself too well to think she wouldn't do it again.

In her more defensive, less generous moments, she blamed Sadie for giving her the courage to love. Sadie had been the first chink in her carefully wrought armor, the horseshoe nail* – the first domino of Mary's long-practiced caution to fall.

* "For want of a nail the shoe was lost. For want of a shoe the horse was lost. For want of a horse the rider was lost. For want of a rider the battle was lost. For want of a battle the kingdom was lost. And all for the want of a horseshoe nail." –Benjamin Franklin

Many thanks to my Sherlockian sisters who took a look at this for me before I posted it – your feedback was invaluable!