The trio raced to the hollow, Sherlock's hands gripping the handle of the car tightly as he drove as fast as he dared. He pulled up as close to the woods as possible, and Marie and John darted out quickly, Sherlock following after he'd pulled the brakes on the car.

Marie had pulled out her gun as they ran to the Hollow, although she kept it tucked behind her back for now. John looked a little surprised but Sherlock didn't even glance at it as they raced through the woods. They arrived just as Henry was placing his pistol into his mouth.

"No, Henry, no! No!" Sherlock shouted as he skid down the hill into the Hollow. John and Marie flanked on each side of him and Marie's grip on her gun tightened as Henry waved his gun wildly, screaming as he flailed away from their torchlight: "Get back. Get – get away from me!"

John tried to calm the young man as he said soothingly: "Easy, Henry. Easy. Just relax." He lifted his hand slowly, soothingly but Henry said shakily as he pointed his gun at them: "I know what I am. I know what I tried to do!" His voice returned to hysterical.

"Just put the gun down." John said, trying to calm the man but keeping his voice firm. "It's okay-" Henry shrieked: "No, no, I know what I am!" Sherlock said pacifyingly: "Yes, I'm sure you do, Henry. It's all been explained to you, hasn't it? Explained very carefully."

John and Henry looked confused and Henry asked: "What?" Marie kept a tight grip on her gun as Sherlock explained in the same soothing but firm tone: "Someone needed to keep you quiet; needed to keep you as a child to reassert the dream that you'd both clung on to, because you had started to remember."

Marie's grip tightened as Sherlock stepped forward slowly, imploring Henry: "Remember now, Henry. You've got to remember what happened here when you were a little boy." Henry said in a broken voice: "I thought it had got my dad – the hound. I thought ... Oh Je... oh Jesus, I don't – I don't know any more!"

The man started to put the gun back in his mouth and John cried in alarm: "No, Henry! Henry, for God's sake!" Sherlock interjected hastily: "Henry, remember. 'Liberty In'." Two words; two words a frightened little boy saw here twenty years ago."

Henry paused and Sherlock continued quickly: "You'd started to piece things together, remember what really happened here that night." He paused and he prompted: "It wasn't an animal, was it, Henry?" Henry paused, straightening up as he stared at Sherlock as Sherlock continued encouragingly: "Not a monster. A man."

Henry's face slackened and Marie could see he was remembering the truth. She watched him carefully as Sherlock continued to explain: "You couldn't cope. You were just a child, so you rationalised it into something very different. But then you started to remember, so you had to be stopped; driven out of your mind so that no-one would believe a word that you said."

"Sherlock!" Lestrade called, having arrived. Sherlock glanced over as Lestrade clambered his way down to the Hollow while John said to Henry soothingly: "Okay, it's okay, mate."

John slowly walked forward, gently taking the gun from Henry's loose grasp. Marie relaxed just a little bit now that the gun was out of the half-mad man's grasp, but she was still tense as she glanced around. There was no way it would be this easy- Frankland would have wanted to ensure Henry was silenced.

Henry mumbled uncertainly: "But we saw it: the hound, last night." He looked at Sherlock as he pleaded: "We s... we, we, we did, we saw..." Henry's voice broke and Sherlock nodded as he explained: "Yeah, but there was a dog, Henry, leaving footprints, scaring witnesses, but it was nothing more than an ordinary dog."

Henry's face contorted and he began to shake his head but Sherlock explained firmly: "We both saw it – saw it as our drugged minds wanted us to see it. Fear and stimulus; that's how it works." He paused and when Henry looked uncertain Sherlock said softly: "But there never was any monster."

Of course, it was at that moment that a howl ripped through the air and something began to snarl above them. They all looked up, and John said in alarm as they all saw something prowling on the rocks right above them: "Sherlock..."

Sherlock staggered a little, fear gripping him but then Henry started to break down hysterically: "No. No, no, no, no!" Sherlock tried to calm the man, saying urgently: "Henry, Henry..." Marie's breathing quickened as she saw the gigantic shadow prowling above them. This can't be happening.

"Sherlock..." John said urgently as Henry screamed: "No! No!" "Henry!" John tried to calm and Marie gasped as they saw the hound appear right above them, its eyes glowing red. Lestrade gasped: "Shit!"

John asked in confusion: "Greg, are you seeing this?" Sherlock looked around wildly as John said with forced calm: "Right: he is not drugged, Sherlock, so what's that?" As the creature snarled John yelled, all calm gone: "What is it?!"

Sherlock snapped, his nerves at their end: "All right! It's still here ... but it's just a dog. Henry!" Sherlock tried to convince the trembling man urgently: "It's nothing more than an ordinary dog!" At that moment the hound howled, and Lestrade cried as they all backed away: "Oh my God."

The hound began to climb down the hill, snarling ferociously and Lestrade yelled: "Oh, Christ!" Suddenly they heard breathing behind them and Sherlock whipped around to see a man in a mask hiding in the shadows, hidden behind the fog.

Sherlock dashed over and pulled the mask off, but he staggered back as the face before him morphed into the smiling face of Moriarty. "No!" Sherlock cried as Marie's face also paled. She was glancing between the figure and the hound while Sherlock shouted, fighting with his own mind: "It's not you! You're not here!"

He pulled the figure around and out of the fog to see it was Frankland, the man's hand clasped desperately over his mouth and nose. Sherlock breathed heavily and then realization hit him. "The fog." He muttered.

"What?" John asked and Sherlock shouted as he looked around at the thick fog that was always flooding the Hollow: "It's the fog! The drug: it's in the fog! Aerosol dispersal – that's what it said in those records. Project HOUND – it's the fog! A chemical minefield!"

At his words, Lestrade and John were trying to block their noses, while Marie was focused completely on the still snarling and growling hound before them. As it came closer, Frankland yelled in terror: "For God's sake, kill it! Kill it!"

The hound reared back, getting ready to hurl itself at them as it bared its teeth and snarled. Lestrade raised his gun and shot around the hound, and it didn't even flinch. It leapt. A shot sounded.

The hound fell in the corner, dead with a bullet straight to the heart. They all stood, breathing heavily. Lestrade looked confused as to where the shot had come from while John stared at the stone-faced Marie. Her face was completely white but her hand was steady as she lowered the gun. But it was the look in her eyes that cause John to step towards her in worry.

Sherlock glanced at her before he dashed over to Henry, dragging the man to the corpse as he ordered: "Look at it, Henry." Henry protested, trying to stay away as he whimpered: "No, no, no!"

Sherlock just shoved the man forward as he ordered: "Come on, look at it!" Henry stared as they all saw that it was an ordinary large black dog. Henry whispered: "It's just..." He turned abruptly to glare at Frankland as he spat: "You bastard. You bastard!"

He lunged at the man, tackling him to the ground as he screamed: "Twenty years!" John dashed to pull Henry back but the hysterical man gripped Frankland's jacket front tightly as he screamed: "Twenty years of my life making no sense! Why didn't you just kill me?!"

Sherlock and Lestrade moved to help John pull Henry away. John and Lestrade restrained Henry as Sherlock explained sharply: "Because dead men get listened to. He needed to do more than kill you. He had to discredit every word you ever said about your father, and he had the means right at his feet."

Sherlock pointed his torch at the man in disgust before he glanced around the Hollow, explaining: "A chemical minefield; pressure pads in the ground dosing you up every time that you came back here." Henry was finally calming down and John and Lestrade let him go wearily.

Sherlock spread his arms as he walked towards the centre of the Hollow, saying delightedly: "Murder weapon and scene of the crime all at once. Oh, this case, Henry! Thank you. It's been brilliant."

"Sherlock ..." John muttered warningly. "What?" Sherlock asked as he turned back and John snapped: "Timing." Sherlock glanced around, taking note of the blank look on Marie's face. He asked quietly: "Not good?" John grimaced but Henry suddenly piped up: "No, no, it… it's okay."

He stared at Frankland as he continued: "It's fine, because this means ... this means that my dad was right." Henry stepped forward and John and Lestrade guarded him, but Henry didn't notice, too focused as he said with a breaking voice: "He found something out, didn't he, and that's why you'd killed him – because he was right, and he'd found you right in the middle of an experiment."

Henry spat the word. Suddenly there was a growl behind them, and while all the men turned, Marie's eyes narrowed. Frankland had taken the opportunity to turn and run, and Marie ran after him in anger. Sherlock turned as Marie passed him, surprised and concerned.

"Marie?!" He asked and then saw where she was going and yelled: "Frankland! Frankland!" They all ran after the man as he fled, Marie gaining on him so quickly Sherlock and John worried Lestrade would notice something fishy. Thankfully- or maybe not, depending on how you looked at it- Lestrade was at the very back.

As Lestrade lagged a little, John yelled: "Come on, keep up!" Sherlock shouted: "It's no use, Frankland!" Frankland glanced back to see the silent brunette woman catching up right behind him. In a panic, he climbed a barbed fence, crashing down into a field. He scrambled upright and backed up as he stared back at the woman who'd stopped at the fence.

His foot pressed something and there was a metal click, and then a beeping sound that warned him about what he'd stepped on. He glanced down and took a shaky breath as he looked up at the silent figure standing by the fence. She was staring at him with cold eyes, and he almost didn't recognize her as the same woman he'd met before.

But as his breathing hitched, her face changed. She looked down at his foot and then slowly up at him. "I can get you off that safely." She said in a monotonous voice. Frankland stared at her but then looked behind her. Sherlock and John were just emerging from the woods and Frankland smiled wryly.

"Never." And he stepped off the mine. Marie didn't even flinch as the whole area exploded, knowing she was safely out of range. The men all flinched as they stopped just outside the woods, staring at the explosion. Henry leaned back against a tree in defeat while Lestrade turned away sadly.

John spotted the slight figure by the fence and he slid his eyes over to his flatmate. Sherlock's eyes had also zeroed in on the woman who stood watching the flames die down. John murmured to Lestrade: "Come on, let's get Henry home." Lestrade looked surprised but John led the two men away firmly before the DI could ask or look towards the brunette woman standing by the fence.

Sherlock moved to where Marie stood, stopping beside her. "He'd rather have died than be taken in to face his crimes." She said flatly and Sherlock hummed. "Are you alright?" He asked suddenly.

"Why wouldn't I be?" She asked without emotion. Sherlock turned to face her fully, looking down at her as he said sternly: "You just watched a man die before you." Marie's shoulder tensed a little but she replied flatly: "He's not the first, tenth, or even hundredth."

"He still died before you." Sherlock said quietly. She drew in a sharp breath but didn't move. He waited before he said quietly: "In the fog, when I pulled the mask off Frankland, I saw him. Moriarty." She tensed and Sherlock continued: "I know you saw the same thing."

She turned to him at last, tears shining in her eyes. Sherlock pulled her into a hug as she sobbed: "If I'd just shot him in the leg or something earlier, brought him down before, he'd still be alive. But I couldn't. I saw Jim's face and it was like I just shut down."

Her words came faster, almost running into each other in her agitation: "My body just took over because my mind couldn't work. And when it did, I chased an old man into a mine field, knowing I would come out fine. I chased him with the intent to kill. Is my natural instinct really to kill? Is that what I am, really?"

Her voice had become hysterical and Sherlock interrupted firmly, pulling back to look her straight in the eyes as he said: "No. You've been trained to react, habits beaten into you. That's why your body reacted the way it did, but Marie, you are not a killer."

"How-?" She began but Sherlock interrupted gently: "Because if you were, you would have shot him on the spot. Your heart chose to chase him, to bring him to justice. You couldn't shoot him because you didn't want to hurt him. And I'd bet that when he stepped on that mine, you wanted to save him."

A tear spilled over as Marie whispered: "Do you really believe that?" "Without a doubt." Sherlock replied. Marie took a shuddering breath, before she leaned her head into Sherlock's chest. He wrapped his arms around her comfortingly as she began to cry, her tears flowing thick and fast.

Marie couldn't even remember the last time she'd felt so shaken to her core, the last time she had allowed herself to wail as she did now, sobbing her heart out. Sherlock just held her silently, rubbing soothing circles on her back as he rested his chin on her head, staring out at the minefield.

The next morning, John was sitting outside eating breakfast when Sherlock walked up, carrying two cups of coffee. As he sat down beside his flatmate, John asked quietly: "How is she?"

"She's better." Sherlock replied shortly. John nodded, glancing back at the inn where Marie was sleeping. He was worried but knew Sherlock would have taken care of the brunette, so he didn't question any further. They sat in comfortable silence for a moment before John remembered something.

"Listen: what happened to me in the lab?" He asked and Sherlock glanced at him, then at his plate. "D'you want some sauce with that?" He asked abruptly, turning away to grab it and John mused: "I mean, I hadn't been to the Hollow, so how come I heard those things in there? Fear and stimulus, you said."

Sherlock had turned back with the condiments basket, and he said dismissively as he looked through the basket: "You must have been dosed with it elsewhere, when you went to the lab, maybe. You saw those pipes," John nodded and turned away as Sherlock continued: "pretty ancient, leaky as a sieve; and they were carrying the gas, so ... Um, ketchup, was it, or brown ...?"

He tried to shift topics when John interrupted: "Hang on. You thought it was in the sugar. You were convinced it was in the sugar." He looked at Sherlock who averted his eyes, before saying abruptly: "Better get going, actually. I'll fetch Marie." He checked his watch. "There's a train that leaves in half an hour, so if you want ..."

John's face changed as realization dawned on him and he closed his eyes as he groaned: "Oh God. It was you." He looked at Sherlock as he sighed: "You locked me in that bloody lab."

Sherlock shifted uncomfortably as he said: "I had to. It was an experiment." John repeated incredulously: "An experiment?!" "Shh."Sherlock said uncomfortably and John lowered his voice but said just as angrily: "I was terrified, Sherlock. I was scared to death."

Sherlock whispered his explanation quickly: "I thought that the drug was in the sugar, so I put the sugar in your coffee," John sighed, "then I arranged everything with Major Barrymore. It was all totally scientific, laboratory conditions – well, literally."

John took a deep breath when another thing occurred to him. "Marie knew, didn't she?" He groaned and Sherlock muttered: "Maybe." John groaned: "Of course she did." Sherlock grimaced as he added: "But she only figured it out later, so don't blame her."

John sighed. "So that was why she looked so guilty and why she looked angry with you." He muttered and Sherlock explained: "Well, I knew what effect it had had on a superior mind, so I needed to try it on an average one." John paused and Sherlock said wearily: "You know what I mean."

John grit his teeth before he started back on his breakfast as he muttered: "No, it was just because you love her." Sherlock stayed silent and John added: "And it wasn't in the sugar." Sherlock shrugged as he said: "No, well, I wasn't to know you'd already been exposed to the gas."

"So you got it wrong." John said pointedly and Sherlock muttered sulkily: "No." John snorted as he said firmly: "You were wrong. It wasn't in the sugar. You got it wrong." Sherlock conceded: "A bit."

He blinked before adding petulantly: "It won't happen again." John snorted again, and then paused. "Any long-term effects?" He asked and Sherlock replied: "None at all. You'll be fine once you've excreted it. We all will." He looked back at the inn, thinking about Marie.

John saw the worry in Sherlock's eyes and he joked to try and lift the other man's spirits: "Think I might have taken care of that already." Sherlock chuckled and John grinned as he went back to his breakfast.

Sherlock's eyes suddenly zeroed in on Gary, who nodded to Sherlock in greeting as he served a different table. Sherlock paused and then stood up abruptly. John looked at him, startled as he asked: "Where're you going?"

"Won't be a minute." Sherlock replied and then looked down at John. He smirked as he said: "Gotta see a man about a dog." John saw where Sherlock was headed and he snorted before turning back to his meal. Neither man was aware of Marie watching them from the windows, her phone against her ear as she listened to the man on the other end.

"I accept." She murmured as she watched Sherlock with sad eyes.