Part One.

When she was a small child, no older than five, Thea would have terrifying nightmares of a faceless woman claiming to be her mother. The entity would stand over her bed, a pale hand reaching out to her, as a screeching voice demanded that Thea come with her. She would wake up screaming, her hands covering her ears as her father ran into the room. The conversation was always the same.

"I saw Mummy again. She was trying to take me."

"It's just your mind's portrayal of her, Thea. Hush, sleep now."

"I can't, Papa, she's going to come for me again."

"She loved you, she would never hurt you. Not even in your dreams. Lie down, dear."

At seven years old, she clung to her father's jumper as he attempted to pry her from him, avoiding her pleading eyes. They were at his parent's cottage in the countryside, a quiet little place that had been full of sunshine and happy memories – up until now.

"Thea, I have to go, let go of me."

"I don't want to stay with Nan, I want to go with you!"

But he kept shaking his head, repeating, "I've already told you no, now let. Go."

"NO!"

And then suddenly her grandmother was pulling her away, pulling Thea into her arms. And she screamed, as loud as her little lungs would allow, kicking and fighting as hard as she could. Her screams drowned out whatever her grandmother was saying to her father, but it didn't matter, nothing mattered anymore. She watched through blurry eyes as he walked away, carrying a suitcase and little else to his car. He climbed in, never looking back at her, and turned over the engine, driving away without saying a single goodbye.

Thea managed to fight her way from her grandmother's grasp and ran out into the dirt road, trying in vain to catch up to him, "Papa, please! Don't leave me!" She fell to the dirt and pulled her knees to her chest as the dust blew up around her. She had never felt so alone.

But here she was now, eleven years later, trusting him with her life. Sherlock stood less than two metres away, his back to her as he pointed a loaded pistol at a bomb lying on the tiled floor of the pool deck. To her left, their only friend, Dr John Watson, sat with his back to a changing stall, his palms flat on the ground on either side of him. His mouth was agape, awaiting their fate with wide eyes. At his chest were three snipers' lasers, identical to the ones at hers. Sherlock was donning several of his own.

Only moments before, James Moriarty had strolled back into their lives with a threat to end them immediately and without hesitation. The trio had gotten in his way, you see, and such nonsense couldn't be tolerated in his line of work – in which he arranged an array of crimes comparable to booking a holiday.

The man in question stood at the deep end of the pool, his dark hair slicked back, hands in his pockets, and his mouth set in a grim line. His suit was immaculate and clean-cut, with freshly-shined shoes and a crisp white handkerchief in his breast pocket. But beyond all that, his eyes were what scared Thea the most. She had never seen anyone's eyes so incredibly devoid of life. If she didn't know better, she would have thought him dead inside. He was more dangerous than she could have ever imagined, insane to a degree she didn't think possible in a human being.

She kept her gaze on him, ignoring the cold feeling that swept through her bones. She'd told her father to do whatever he deemed necessary to keep Moriarty from wreaking havoc. She prayed, for once in her life, that he would be a good man and do the right thing.

And just when the tension had reached its climax, the tinny introduction to "Stayin' Alive" began echoing through the room.

Thea's brows furrowed as her father glanced back at her and John, but she shook her head slightly as she mouthed, "It's not us."

Then Moriarty closed his eyes and sighed in exasperation. All eyes turned back to him.

"D'you mind if I get that?" he asked as if they were all out to dinner and it was a minor inconvenience.

Sherlock shook his head and motioned with the handgun, nonchalantly replying, "No, no, please. You've got the rest of your life."

James pulled his mobile out and answered casually, "Hello? …Yes, of course it is. What do you want?" He mouthed a sarcastic, apologetic "Sorry" to Sherlock, before turning around for a moment. Then suddenly he spun back around, his face full of fury as he roared into the phone, "SAY THAT AGAIN!"

Thea glanced at John before looking at her father, his eyes quickly finding hers as a frown pulled at his mouth.

Moriarty continued venomously, "Say that again, and know that if you're lying to me, I will find you and I will ssssssskin you." He drew out the 's' of the word, hissing into the phone. And then suddenly he said quietly, "Wait." Then he placed the phone at his chest, his eyes drowning in the depths of the pool as he walked toward the bomb. Her father swiftly adjusted his grip on the pistol, but the madman stopped just short of the coat and looked thoughtfully at the floor. "Sorry." His eyes lifted to meet Sherlock's. "Wrong day to die."

"Oh," the detective answered casually, "Did you get a better offer?"

James glanced down at the phone before turning and starting to walk away. "You'll be hearing from me, Sherlock." Then he raised his free hand and snapped his fingers, causing the lasers pointed at the trio to disappear completely. He pressed the phone back to his ear and walked through the door he'd come through, saying, "So if you have what you say you have, I will make you rich. If you don't, I'll make you into shoes…"

And then he was gone yet again.

Sherlock followed him some ways, his eyes scanning the balconies overhead but finding nothing of substance. He peeked through the door but turned back to John and Thea with hard eyes.

After a moment, she found herself finally able to breathe. John stood, pressing a hand lightly to her back as she doubled over, her hands on her knees.

"What happened?" he asked Sherlock, and the detective shrugged, pulling his own mobile from his trouser pocket. Still between his fingers was the memory stick he had intended to give to Moriarty. In his other hand, the gun hung limply, still cocked.

"Someone changed their mind. The question is: who?" he answered simply before pressing the mobile to his ear. "But first…" He paused, then half-smiled as the recipient answered. "I promised I'd call."

Then he held out the phone to Thea, who straightened and furrowed her brows before taking the mobile and placing it next to her ear. "Hello?"

"Thea! They found you!" a warm voice exclaimed, and her other hand pressed to her mouth as a jolt ran through her veins.

"Matthew, oh my god. I'm so sorry," she whispered, holding back tears of relief at the sound of his voice. Her father touched her shoulder lightly and motioned to the door behind them. She followed her boys as they lead the way back outside. "I should have texted you something less cryptic, I was just so scared, and things happened so fast – "

"It's alright, I'm just so glad you're safe," he interjected, laughing slightly. "I don't suppose you still want me to come for dinner?"

She glanced at the time on the mobile; it was quite late, but she had a feeling that she wouldn't be able to sleep tonight. "I want nothing more than to see you right now. I'm not quite sure where we are exactly, but feel free to head over. Mrs Hudson will be more than willing to let you in."

"I'll be there. Stay safe, love."

"I'll try my best."

Thea hung up and handed the phone back to her father as they slipped back outside. She'd never appreciated the cool night air against her skin as much as she did in that moment, and she silently vowed to cherish each minute that she was alive – for there would be a day when James Moriarty would come for them again.

And she knew they would not be so lucky a second time.

The ride back to Baker Street was a quiet one between the three of them. They pulled up to 221B and emerged single-file onto the sidewalk, murmuring thanks and passing cash to the driver before Sherlock unlocked the front door. Thea felt a shock of relief at the sight of the building, having earlier been afraid that she'd never see it again.

She took the lead as they climbed the stairs, and when she reached their flat, she saw Matthew standing, his back to her, in their living room. He turned to her, his storming eyes catching her sapphire ones, and gave her a comforting lopsided grin. He was wearing a hunter green jumper with a beige-striped button-up underneath, dark jeans, and casual loafers, and Thea drowned at the sight of him. She immediately threw her arms around him, trying to dam the flood of tears behind her eyes.

"I'm sorry," she repeated into his neck, and he just stroked her hair, holding her close to him. He smelled of musk and vanilla rum, an intoxicating combination.

"Don't be, love. I knew you'd come back to me," he murmured, and they stayed like that until they heard Sherlock clear his throat behind Thea.

Thea broke from their embrace and ran a hand over the back of her neck, "Right, introductions, sorry. Hem, this is my father, Sherlock Holmes, and our friend and flatmate, Dr John Watson."

Matthew smiled warmly and shook their hands, "Pleasure to meet you both, really. Thea's particularly enthusiastic when she talks of you two."

Sherlock eyed the young man with a hawk's precision, but Thea could see him struggling not to immediately deduce everything about Hem. She appreciated the effort all the same.

John gave a small chortle and said to the artist, "I hope good things are being said on my behalf. Have you had a bite to eat? I know we had something planned for tonight, and well… We've been… busy, but we could order something in."

Matthew laughed nervously and ran a hand over his dark hair, "Actually, I went a bit overboard and uh…" he motioned to the kitchen and the residents of 221B glanced over to see a full spread on the table. Thea's jaw dropped as she walked forward. The table had been set for the four of them, with food piled on serving platters at the ready.

"Hem! You didn't need to do this," she exclaimed, looking back to him. He shrugged.

"It was the least I could do. You three had already dealt with enough for one night, and there were fresh groceries at the ready... I really don't mind."

John laughed slightly and raised an eyebrow as he moved toward the kitchen. "Well, I'm famished. Shall we?"

Sherlock glanced at the artist and nodded once, taking off his coat and scarf as Thea did the same. Hem took the coat from her and hung it next to her father's things, gesturing for Sherlock to go ahead of him. The detective remained stone-faced as he moved to sit at the head of the table, across from John. Thea squeezed Hem's arm as she passed him, giving him a small smile of encouragement.

They sat and immediately began digging into the steaming piles of food – Sherlock even took small portions of the offerings, if anything, to appear grateful. But his intentions were more fixated on conversation than anything.

"What do you do for a living, Mr Hemingway?" he asked inquisitively, his baritone stricter than usual. His daughter hissed, "Papa" and he shared a glance with her before adding, "Out of curiosity."

Hem didn't seem fazed. "Matthew, please. I'm an art talent scout and critic, essentially, for a small Swiss publication. I do a lot of travelling around Europe, finding little-known artists and writing spotlight features for them."

"Is it lucrative work?" Sherlock pressed, and Thea gave a small kick under the table. He grimaced and returned it in full.

"Thankfully. I was fortunate to be offered the job right after I graduated uni."

John chewed in thought as he asked, "Where did you attend?"

"University of the Arts in London. Majored in fine art with honours. Top of my class."

He hummed in response, "Quite impressive."

"Thank you, sir."

There was a quiet lull in conversation, and as Thea set down her wine glass, she pored over the details of their eventful evening. "Dr Watson?"

"John – you can call me – Nevermind." The doctor shook his head. "You were saying?"

"I was wondering," she started, "How did you end up at the pool? Did Moriarty kidnap you?"

Matthew furrowed his brows as he sipped his wine, "Moriarty? Is that the evil mastermind behind… well, everything?"

Thea nodded, looking to him as she spoke, "Unfortunately. He's – what's a good word for him? –deranged?"

"That's too tame," John chuckled, "But to answer your question, I don't entirely remember. We got back to the flat after solving West's murder, and when we discovered you weren't here, I decided to go to the Yard to alert Lestrade." He thought back to that moment as he chewed, trying to remember, "I think I hailed a cab, and when I got in…" Then he nodded, "That's right, I got in and then another man tried to get in and I told him the cab was taken. He didn't say anything, just stuck something in my arm."

Thea grimaced at the memory of the needle in her neck, touching the spot lightly, "Benzodiazepine. He used it on me, as well. Undoubtedly the same dose – but it would've affected me a lot more. He was surprised I woke up when I did, possibly thought I'd stay unconscious longer."

"Wait, you were drugged?" Hem asked suspiciously, "Shouldn't you be seeking treatment?"

Sherlock scoffed, picking at his food. "If it were a harmful quantity, she would be in a coma. There's no need for dramatics."

"This coming from the man who chose the pool where Carl Powers died as a battleground against his enemy," the detective's daughter shot back, and her father pursed his lips begrudgingly.

"I didn't strap a bomb to anyone."

She snorted. "I didn't realise we needed to start distinguishing between you and Moriarty in such a capacity."

Sherlock put his fork down in annoyance and stood, buttoning his jacket as he did. "I think that's enough intellectual battling for one night. Mr Heming – sorry. Matthew – I thank you for the meal, but I'm not one for digestion, it slows me down. I'll excuse myself to the living room now, shall I close the doors?"

Thea shook her head, "Not all the way, but if you'd like a little privacy I won't argue."

He made a noise of acknowledgement and nodded once at Matthew before turning to the living room, closing the sliding French doors just enough that the room felt smaller and more intimate. Matthew glanced at Thea with a small smile, and John cleared his throat with a small laugh.

"Well I think he likes you, Matthew," he chuckled, and Thea bit her lip with a grin.

A little while later, after much conversation and laughing, Thea and Matthew stepped into cleaning the kitchen while John packed away the food, cautiously peeking into the fridge before placing things inside. As they were washing dishes, there came the low sound of the violin being played. Thea glanced at the living room, her heart swelling, as Matthew stopped for a moment and listened. It was a slow, tranquil melody with sad undertones, but beautiful all the same.

He turned with his back to the counter and leaned against it, drying his hands, "Is there anything he can't do?"

To which both John and Thea immediately responded with variations of "He doesn't think so."

Matthew laughed, shaking his head. They continued cleaning and drinking wine with John against the backdrop of Sherlock's composition, and when the kitchen was tidy, John looked at his watch.

"Blimey, later than I thought. I guess I'll bid you two good night," he yawned, starting for the stairs.

"'Night, Dr Watson," Thea called behind him, sticking her tongue at him as he pinched the bridge of his nose. Then he was climbing the stairs, shaking his head and muttering something being a brat. She looked back at Matthew, who quirked an eyebrow at her.

"Any particular reason you refuse to call him 'John'?"

"You must have missed the part where he looked exasperatedly at me, as if the very idea of me exhausts him."

Matthew chuckled, wrapping an arm around her shoulder. "He's right. You are a brat."

She playfully shoved him and laughed, stepping away to peer through the sliding doors. Hem joined her, and they watched as Sherlock played at the window, pausing every so often to make changes in notes or adjustments to the flow.

"I could watch him for hours," Thea murmured thoughtfully, pressing her cheek to the door. "I used to as a child, before things were strained. I would sit on the floor of our tiny living room – back in those days we lived in a one-bedroom cottage near my grandparents in the countryside – and he would stand at the huge window, looking out to the garden, and he'd play for the entire day. He'd forget to make lunch, but I never complained. The music was so beautiful, I never wanted it to stop." She closed her eyes, going back in time. "I can hear it still, when I think of that cottage."

Hem leaned over and pressed a kiss to her hair. "It sounds absolutely lovely."

"It was, for a time." With a sigh, she turned from the doors and closed them behind her. "So, what plans do you have for tomorrow?"

He shrugged, his hands disappearing into his pockets as his eyes glazed over her. "Not much, I was thinking I might stop by the studio for a bit. Would you want to come with, see where I disappear to?"

"I'd be delighted," Thea grinned, then she checked her watch. "It's pretty late, did you want to stay the night? I know you don't have anything to change into but…"

"That's alright," Hem replied, taking her into his arms, "I'll stay."

Thea wrapped her arms around his waist, taking in the smell of vanilla once more, then she untangled herself from him and led the way upstairs. She hoped for a brief moment that she remembered to clean her room earlier, though she'd no doubt let it slip her mind. Once in her room, she haphazardly gathered her piles of schoolwork and free-writing on her desk, shoving it into the top drawer.

"I would have tidied a little more if I'd known you were staying over," she laughed nervously, running a hand through her wild curls.

Hem closed the door behind him and pulled her in for a chaste kiss, "It's charming." His eyes traced over the blue and grey comforter and sea of pillows, then he was looking at her multitude of tall bookcases. She had three of them, filled and overflowing with a wide variety of novels, ranging from classics like Little Women to the Norton anthology to science fiction including Nightfall and Ender's Game. "Your collection is marvellous. I mean, truly. It's got a little bit of everything."

"It'd better, I've spent so many years building it up to such," Thea teased, sitting on the bed and admiring her work. "Took a lot of Christmases and guilting my grandparents and uncle."

Hem walked up to one and began running his hand over the spines of her books, then his hand dropped and he turned to her. He bent towards her, his knuckles digging into the bed on either side of where she sat, before he kissed her deeply. She returned it, her hands tangling in his hair. She lowered herself onto her back, dragging him with her, and wrapped a leg around his waist. He started kissing her jaw, working his way to her neck.

"I never thanked you for dinner," Thea breathed, and Hem gave a small laugh into her ear.

"No need, I just hope you saved room for dessert," he whispered sensually and bit her neck. She squealed slightly in pleasure and pulled him closer to her.

When he found the button of her jeans, she couldn't help but think that she was so very lucky indeed to be alive.

AN: Hello, hello, hello! I'm back, yet again, with another Thea Holmes installment! I've actually had this chapter finished for a few days now, but I was having internet issues at my parents's house, so I had to wait for that to be sorted.

I'm so excited to give you this glimpse into Trust Me! I think it really sets the tone for the whole story - a little foreshadowing if you'd like.

As always, leave a review, give me your ideas as to what you think will happen. I crave your criticism. Favorite/follow for more updates. They're sure to come quicly!