Three hours later, Sherlock's patience was rewarded. Just as the clock passed ten o'clock, the back door creaked open and a shadowy figure crept into the living room, carrying a thick duffel bag and making swiftly for the Thatcher bust.

Just as the figure grabbed the bust, Sherlock switched on the lights, alerting the intruder to his presence as he asked: "It would be much simpler to take out your grievances at the polling station."

The masked figure turned instantly, a gun already raised in his hand while he stuffed the bust into the bag. Sherlock reacted swiftly, grabbing the gun with both hands and pulling it harshly while hitting the other man's wrist to force him to let go.

The other man reacted by swinging his heavy duffel bag at Sherlock, but Sherlock blocked it instantly, and shoved it off, causing the bag to fall harmlessly to the ground. Sherlock quickly threw in a punch at the man's exposed face, but the man retaliated with a quick elbow jab to Sherlock's face.

Sherlock blocked the next punch but missed the one after that – and he winced slightly as the punch landed squarely on his cheek and eye. Ignoring the throbbing that indicated he was definitely going to have a bruise, Sherlock threw a few quick, sharp punches back at his assailant.

The man was good, clearly highly trained, and Sherlock barely managed to land one solid punch after four blocks. He quickly used his advantage to land another two punches to the man's stomach, adding a kick to the man's shin for good measure.

The man grabbed a nearby bar stool and swung it to hit Sherlock's side, but Sherlock allowed it to fall carelessly to the side as he threw another punch. The man grabbed him, and Sherlock grabbed the man's arms to prevent the man from gaining an advantage.

Unfortunately, the man retaliated by throwing his head forward and head-butting Sherlock, hard, and causing him to drop the gun. Sherlock blinked, dazed, and the man quickly used the moment to grab Sherlock by the head and shove him down onto a wooden cutting board left on the kitchen bar.

He used his leverage on Sherlock's hair to smash Sherlock's head into the board a few times, before Sherlock managed to regain enough control to throw in a surprise punch to the man's stomach. The man doubled over, and Sherlock used the moment to quickly pull off the other man's balaclava.

A man, perhaps mid-thirties and of Indian heritage, glared back at Sherlock. He looked worse-off, Sherlock noted, indicating that while he was clearly highly trained – Sherlock guessed as a mercenary of sorts – he wasn't making much if anything.

Odd for his skill set. Sherlock thought briefly. But perhaps not, if he lost what I think he did.

"You were on the run." Sherlock said aloud as he stared at the other man intently as intently as the man was staring at him. "Nowhere to hide your precious cargo."

He threw in a quick kick to the other man's knee, causing him to grunt. The other man growled and kicked back, but Sherlock backed neatly out of reach.

The other man mimicked his movements, and the two men circled each other as Sherlock continued: "You find yourself in a workshop. Plaster busts of The Iron Lady drying. Clever, very clever."

His voice then turned darker as he added: "But now you've met me, and you're not so clever, are you?"

"Who are you?" The man demanded, and Sherlock answered firmly: "My name is Sherlock Holmes."

The man's jaw tightened and he said darkly: "Goodbye, Sherlock Holmes."

With a roar, he charged Sherlock, who braced himself for impact. But the other man simply tackled him and, using his momentum, threw them both through the glass wall of the pool room. The glass shattered with an ear-piercing crash, and the two men fell with a large splash into the indoor pool on the other side.


At 221B Baker Street, three hours earlier

"And why," Mycroft asked at last as he stared at Marie, "do you ask for this?"

"Because of the people in this world," Marie replied calmly, "only two people know the full truth of my past. And therefore, I can only trust you with this request."

"You don't trust Sherlock?" Mycroft asked, raising a brow and Marie shook her head.

"He's too emotional." She answered softly. "You know that, Mycroft. The advantage is that he can therefore love-"

"Not something I would call an advantage." Mycroft noted dryly, but Marie ignored him as she continued: "But the disadvantage is that it makes him vulnerable in ways you are not."

"Thank you-" Mycroft began, and Marie interjected flatly: "Though I still don't think you're that clever; certainly not as clever as Sherlock believes you to be."

Mycroft frowned at that.


At Sandeford's house

Sherlock struggled against the other man as they fought in the water, the man trying to keep Sherlock underwater. Sherlock punched the man in the stomach, forcing him to release his breath and the man yelled into the water before he let Sherlock go.

Sherlock hastily rose up out of the pool to breathe, the other man following suit instantly. As Sherlock gulped a large breath, the other man grabbed him by the throat, strangling him while Sherlock tried to fight him.

They fell back into the water, the other man pushing Sherlock down deeper while keeping his hands locked around Sherlock's throat, and Sherlock tried desperately to push the other man away. He finally managed to loosen the other man's grasp enough to pull himself back out of the water, both men fighting for air and against each other as they struggled to get the upper hand.

Sherlock maneuvered himself slightly to get a stronger hold on the other man's shirt, and quickly pressed his advantage – this time, he shoved the other man down into the water, trying to make the other man lose consciousness.

Unfortunately, the other man fought back and managed to resurface, breathing in deeply while Sherlock struggled to maintain his advantage. The pair exchanged blows and struggled some more, when the other man spotted something and shoved Sherlock to the side.

Losing his balance, Sherlock stumbled; the other man swiftly used that moment's opening to thrust Sherlock to the side of the pool and, before Sherlock could recover, he shoved Sherlock's head into the Jacuzzi.

Sherlock almost choked, but held his breath desperately, when the machine whirred. His eyes widened as the Jacuzzi came to life, the water spinning and bubbling thanks to the other man switching the machine on.

Sherlock fought to keep his breath while he floundered, trying to shove the other man off of him. Sherlock's assailant fought to keep Sherlock down, using his whole body weight to maintain his leverage.

Sherlock finally managed to pull his head just enough out of the water to breathe, and he glanced to the side as he gasped for air. Quickly reaching out his hand, Sherlock swiped his hand over the photoelectric sensor, switching on the pool tap.

The other man's grip slackened just briefly in surprise, and Sherlock instantly used the moment to thrust his head back and head-butt the other man sharply. He spun around quickly to punch the other man a few times as well, throwing the man off and away before he grabbed the other man in a tight chokehold.

Just as the man started to choke, he shoved Sherlock away, and Sherlock quickly swam to the edge of the pool while the other man fought to get his breath back. The man quickly regained his composure and followed Sherlock out as Sherlock scrambled up the side of the pool. Ignoring the broken window glass, and dashed back into the living room.


Back at Baker Street

"So why trust me, then?" Mycroft asked, looking at Marie from over his clasped fingers as he leaned forward on his arms.

"Because you care as much for Sherlock as I do." Marie said softly. "And I know you would do what you need to, to protect him… even from me."

Mycroft raised a brow and he murmured: "So, that's what this is about."


At Sandeford's house

Sherlock ran for the dropped duffel bag, grabbing the Thatcher bust that had been hastily thrown inside, and as his assailant came charging at him from behind, he turned around and whacked the man in the head with the heavy bust.

The man went crashing down the side of the kitchen bar, landing heavily as Sherlock breathed heavily and stood upright, saying: "You're out of time. Tell me about your boss, Moriarty."

"Who?" The man asked, frowning, as he looked up at Sherlock from his place on the ground.

"I know it's him." Sherlock said impatiently. "It must be him."

The man's eyes narrowed, and he murmured: "You think you understand. You understand nothing."

"Well, before the police come in and spoil things," Sherlock said sarcastically, "why don't we just enjoy the moment?"

He smiled humourlessly as he stated while lifting the Thatcher bust: "Let me present Interpol's number one case. Too tough for them, too boring for me."

Sherlock threw the bust, and the other man flinched away in surprise, but the bust landed harmlessly on the ground where it smashed to pieces.

"The Black Pearl of the Borgias." Sherlock stated, staring down the other man before he glanced down at the broken bust.


At Baker Street

"Very well." Mycroft said at last, staring at Marie intently. "I shall accept to your request."

Marie rolled her eyes as she said dryly: "You'd think I'd asked you something incredibly difficult from the way you responded."

Mycroft simply gave her a look as he answered simply: "You did."


At Sandeford's house

Sherlock stared at the object that had been revealed from inside the Thatcher bust, lying among the broken pieces of plaster.

His eyes were wide and his brows knitted as he slowly reached for the memory stick with the familiar letters written on it: A.G.R.A.

"It's not possible." He whispered in shock as he read the words written across the stainless steel casing. "How could she...?"

He fell to his knees as he reached out to grab the memory stick, picking it up in shock. It was identical, in every single way, to the one he and his then girlfriend Marie, and John, had seen that fateful night at Baker Street when Mary had finally come clean about who she was.

"Everything about who I was is on there." Mary said as she placed the memory stick down on the table beside John's armchair.

But, it couldn't be here.

"The problems of your past are your business." John told Mary firmly. "The problems of your future... are my privilege."

And he threw the memory stick into the flames of the Holmes residence's living room fireplace.

Sherlock blinked, his mind floundering, and he was so distracted he missed his opponent reaching for the fallen gun beside the kitchen bar as Sherlock muttered: "I don't understand. She... She destroyed it.""

"She?"

Sherlock didn't even look up, still stunned at the unexpected turn of events, as his assailant questioned him.

The other man stared at Sherlock, noting the way he was holding the memory stick, and his face crinkled in anger as he spat, raising his gun: "You know her. You do, don't you? You know the bitch!"

Sherlock looked up then, staring at the other man as he snarled: "She betrayed me. Betrayed us all."

"Mary." Sherlock murmured, still dazed, as police sirens sounded outside. "This is about Mary?"

"Is that what she's calling herself now, eh?" The other man questioned darkly, and Sherlock just stared back at the man while Lestrade's voice sounded from over a horn loudspeaker: "Armed police, you're surrounded!"

Sherlock barely even registered Lestrade's voice, still staring at the other man as he hissed, eyes filled with angry tears as he held his gun out menacingly: "Give it to me."

He slowly got to his feet, Sherlock doing the same as he started to refocus. As it became apparent that Sherlock wasn't about to submit to his request, the man yelled angrily: "Give it to me!"

"Come out slowly, I want to see your hands above your head." Lestrade's voice called from outside, while Sherlock didn't even flinch as he stared at the other man with ice-cold blue eyes.

"Nobody shoots me!" The man yelled back. "Anyone shoots, I kill this man!"

"Lay down your weapon. Do it now!" Lestrade shouted from outside, but the man pointed out: "You're policemen, I'm a professional."

His eyes narrowed suddenly as another gun clicked and a shadowy figure appeared behind Sherlock. Sherlock also tensed as he felt the presence behind him, while the other man's eyes darted between Sherlock and the newcomer.

"Shoot him and I promise you, you will miss and you will end up with a bullet in your heart... if you have one." Marie promised darkly, her gun pointed steadily at the other man's chest.

Sherlock didn't look back, though his shoulders were tight with tension, while the other man's dark eyes narrowed as he stared into Marie's cold green ones.

"Who are you?" He hissed, and Marie replied flatly: "You don't need to know."

"Tell me!" He yelled, but Marie was unmoved as she simply kept her gun trained on the man.

"Lay down your weapon!" Lestrade shouted from outside, and the man shouted back though his eyes were trained on Marie: "I'm leaving this place. If no-one follows me, no-one dies."

The man stared Marie down for a second longer before his eyes flickered back to Sherlock.

"Tell her - that bitch." He snarled. "Tell her she's a dead woman. She's a dead woman walking."

"She's our friend." Sherlock replied quietly and darkly. "And she's under my protection. Who are you?"

The man hesitated before his eyes flickered over to Marie and then back to Sherlock as he answered: "I'm the man who's going to kill your friend. Who's Sherlock Holmes?"

Marie's eyes narrowed, but Sherlock answered flatly: "Not a policeman."

The man seemed to pause, and Marie saw his eyes dart away. She quickly ducked as the mysterious man fired his gun, the bullet whizzing over her and hitting the light sensor switch behind. Marie fired a shot in his direction as the man fled, but she heard it miss as he ducked, clearly having expected the shot.

Marie slowly straightened up, staring after the disappearing shadow as the room was thrown into darkness while the house alarms blared, but Sherlock didn't move as he stared after the man while Marie slowly walked over to him.

"Should I follow him?" She questioned quietly, but Sherlock shook his head.

"No." He answered. "He knew Mary; said she betrayed him."

Sherlock looked down at the memory stick in his hand. His eyes narrowed, and he murmured: "We need to talk to Mary."

"Okay." Marie answered, before she punched Sherlock on the arm.

"What was that for?" He complained, wincing as he rubbed his arm – she hadn't exactly been holding back on her hit.

"What was this?" She demanded. "Greg phoned me to let me know they had a police call at the house you'd said you would be at, and that there had been sounds of fighting."

"Well, I had it under control." Sherlock muttered. "I just… got distracted."

His fingers brushed over the memory stick as he spoke, and Marie glanced at it.

"That's what that guy wanted, right?" She asked curiously. "What...? Oh."

She fell silent as she saw the familiar letters.

"Yes." Sherlock agreed. "Oh."