Author's note- So today at 2.21pm the BBCOne twitter account is giving Sherlock news with the hash tag 221Back. I'm so excited and scared! But anyway, I thought I'd hurry up and do another chapter today. This story is getting really tricky for me, so nice reviews are greatly appreciated!

Disclaimer- I own nothing.

Chapter 41

On their way to Scotland Yard, Sherlock briefly explained how he came to know what the glycerol molecule was. Every fairytale needs a good old fashioned villain. Moriarty was playing another game, taking clever little bits from Grimm's fairytales to form a spectacular crime. The witch's house in Hansel and Gretel is just one of those stories, the house- made of sweets and chocolate- made the two children want to go in as they loved the sweets. So Sherlock knew that the glycerol molecule PGPR is used in making chocolate- so it all fit in with the story.

How sickening.

Lucy sat in the middle of the black cab, feeling uncomfortable and suddenly awkward. She felt both Sherlock and John's eyes on her, but she refused to look into their eyes. Everything she'd known over the past several months was falling down around her, crashing to the ground, and she hated the fact that she was questioning the person who accepted her and wanted to help her.

"Are you alright?" John murmured to her.

"I'm fine," Lucy replied in a voice that wasn't her own. Dammit! Why did Moriarty have to mess with her head, using her insecurities to ruin everything. You can't kill an idea though, not once it's made a nice home right in the centre of your brain. Once they got out of the cab, Sherlock looked like he was about to say something to her, but he just furrowed his eyebrows and strode ahead into the police station, with his flatmates hot on his heels.

Greg Lestrade was there to greet them when they got in, his face tired looking and serious. Together, they all started walking to the main room where the police officers were working.

"A fax arrived an hour ago," Lestrade said as he handed the paper to Sherlock. From over the detective's shoulder, John and Lucy could read the words: 'HURRY UP THEY'RE DYING!'

"What have you got for us?" Greg asked the consulting detective.

"We need to find a place in the city where all five of these things intersect," Sherlock muttered, handing the DI a list.

"Chalk, asphalt, brick dust, vegetation and what is this? Chocolate?" Lestrade read the list out aloud.

"I think we're looking for a disused sweet factory," Sherlock interrupted quickly.

"We need to narrow that down... a sweet factory with asphalt?"

"No, no, no," Sherlock muttered, clearly in his element in the midst of a case, "Too general, we need something more specific. Chalk, chalky clay- that's a far more thinner bound of geology."

"Brick dust..." The DI said.

"Building site... bricks from the 1950s." Sherlock murmured, seemingly in his mind palace.

"There's thousands of building sites in London," Greg sighed, running his hands over his face in despair.

"I've got people out looking," Sherlock said as though it was blatantly obvious.

"So have I," Greg seemed a little indignant.

"Homeless network, faster than the police. More relaxed about taking bribes," He smirked as Anderson rolled his eyes. Suddenly, Sherlock Holmes' mobile phone started ringing with dozens of texts. He held the device up to prove a point before checking what he had been sent. Lucy watched him in amazement, she knew deep down that it took a genius to be able to think of all the things he had done already- how could he just make it up?

"John," Sherlock suddenly said, holding up his phone to the ex army doctor, "Rhododendron ponticon, it matches." Referring to the vegetation they found- that now meant that they were able to eliminate a lot of the disused factories. There was a short pause.

"Addlestone."

"What?" Lestrade looked up at him.

"There's a mile of disused factories between the river and the park, it matches everything," The detective spoke quickly as he started to walk away.

"Come on," Lestrade said to the other officers, they all looked at him, "Come on!"

With sirens blaring out loudly, they raced to the disused factories in a record time. Lucy felt her heart beating in her chest, the adrenaline coursing through her with the knowledge that they needed to find the children as soon as possible. Sherlock was on the edge of his seat, and as all of the police cars pulled up outside the building, simultaneously everyone immediately bolted out of the cars to dash into the disused sweet factory. They burst the blue doors open, and got out flashlights to illuminate the dark interior. Donovan barked out orders to officers quickly, telling people to spread out and to look over different places. Lucy followed Sherlock and John, shining her torch around but seeing no-one in sight. Sherlock suddenly darted down, further into the room to a candle on the floor surrounded by colourful sweet wrappers. He bent down to touch the candle.

"It was alight moments ago," he said in a deep voice. Speaking loud enough for the other cops to hear, he said: "They're still here." Lowering his tone again he started talking- almost to himself- "Sweet wrappers... what's he been feeding you?" Standing up, he held in his slender hand a single wrapper. "Hansel and Gretel." Bringing the plastic to his face, he sniffed it tentatively before licking it. He recoiled with a disgusted look. "Mercury!"

"What?" DI Lestrade walked over to him.

"The papers, they're painted with mercury- lethal." He explained, "In all of the stuff they ate."

"He was killing them."

"It's not enough to kill them on their own." He said, "Taking in large enough quantities eventually it would kill them- he didn't need to be there for the execution... Murder by remote control, he could be a thousand miles away. The hungrier they got the more they ate... the faster they died. Neat." A small smile played at his lips in fascination.

"Sherlock." John warned in a hushed tone. Lucy stared in surprise at the detective. She knew he enjoyed his cases, but saying the killing the children that way was 'neat' was a step too far. Unfortunately though it didn't appear as though Sherlock realised how he sounded sometimes.

"Over here!" Came the sudden call from Sally Donovan. Obviously everyone sprinted over to where the officer called from, stopping in their tracks a good distance away from where a young girl sat on the ground next to a young boy who was lying seemingly unconscious.

Lucy watched as they carried the children out of the disused sweet factory. They were taking the young boy to hospital, and the girl would be checked over. To say it was shocking was to say the least. And as the sun started to set on their way back to Scotland Yard, Lucy had to wonder if Sherlock was truly capable of doing such things to these children. If Rich Brook was who he said he was, then that meant that Sherlock created this whole case up. He wasn't capable of it- the troubled teenager tried to convince herself. Or was he?

John had left to go get some food by the time darkness had fallen. Sherlock was left with Lucy in the police station as Lestrade and Donovan started to question the young girl- Claudette.

"You seem pensive. Are you okay?" Sherlock said to the teenager as he came to sit beside her. Lucy immediately felt herself tense up, but forced her body to relax- she felt ashamed.

"Yeah, yeah I'm fine." She replied, "I'm just mulling over how awful it was for the children."

"But they're safe now." The detective said.

"Who did this?" Lucy asked him.

"Moriarty, isn't it obvious? I thought I already said this." Sherlock frowned. Lucy just hummed in reply.

"What if it isn't Moriarty?" She suddenly queried with a whisper.

"Why would you say that?"

"Um," Lucy was caught off guard. "I don't know." She shrugged, grateful that John had chosen that moment to return. He sat beside her and handed her a sandwich. He didn't bother get one for Sherlock, the detective quickly refused, settling instead for a cup of coffee. As the dark haired man paced up and down, John turned to Lucy.

"So how have you been?" He asked, taking a bite of his sandwich.

"Not bad," she replied, eating her own dinner.

"You know, you can tell me if something is wrong." He murmured.

"I know," Lucy smiled at him, "I really am okay." John looked at her for a moment before nodding, knowing better than to press her for answers.

After what seemed like an eternity, Donovan and Lestrade came out of the interview room.

"Right, the professionals are finished," Sally said with a smirk, "If the amateurs go in and have their turn."

"Now remember she's in shock and she's seven years old," Lestrade stopped Sherlock pointedly, "Anything you can do to..."

"Not be myself." Sherlock finished for him.

"Yeah, might be helpful," Greg smiled as Sherlock put his coat collar down. Lucy stayed sitting as Sherlock entered the room with John behind him. There was a long pause.

Suddenly a scream emitted from the interview room. Lucy looked up in shock as it continued.

"Get out!" Greg yelled at Sherlock, pulling him out of the room. Lucy frowned.

"The girl screamed at him." John murmured to her with a worried expression.

"Why?" Lucy asked. He shrugged.

Lucy looked at Sherlock as he stood, looking outside the window in quiet. Her thoughts kept overcrowding her mind. Something was wrong with it all. Why would the girl just scream like that?

"Something about Sherlock reminds her of the kidnapper." Greg's voice suddenly cut through her thoughts and she stared up at him with wide eyes.

What if she screamed because Sherlock was the kidnapper? Lucy ran a hand over her face. She must be over thinking this. Unconsciously, she scratched at her arms, feeling a few of her fresher cuts start to bleed again and she sighed in relief at the slight numbing rush of endorphins it gave her.

"Well don't let it get to you I always feel like screaming when you walk into a room," Lestrade said to the detective with humour, "Actually so do most people." Lucy couldn't help but stifle a small laugh.

As John went outside, Greg pulled Lucy into his office.

"How are you doing?" He asked her calmly.

"I swear everyone is asking me that today," Lucy sighed.

"You don't seem okay." He murmured gently. "And there are blood stains on your arm."

"What?" Lucy looked down, panicked. She had dark clothing on, but faintly, you could see a small discolour patch. "Dammit." She grumbled. "It's nothing I must have scratched it."

"You were scratching at your arm back there." He said softly. "What's going on?"

"Nothing really is going on," Lucy told him, "Just the usual."

"You sure?"

"Positive."

"Alright." He looked at her sceptically. "But you know where I am if you ever need me."

"Yeah, thanks," She smiled. There was a pause before she wrapped her arms around him in a hug. Lestrade was rather surprised, but he quickly wrapped his own arms around her slim figure. He knew something was wrong, but much like John he didn't want to push her into saying anything.

Lucy let go and gave him a smile before joining her flatmates outside. She couldn't shake the thoughts out of her head though. What if Sherlock was found to have been the kidnapper? What would happen then? Was she in any danger of him? She looked at him, but he was just staring straight ahead.

She knew something bad was going on. Despite what Rich Brook had told her- she couldn't let that cloud her judgement over the detective. Knowing Moriarty... that could just be yet another lie. But as she watched Sherlock get into his own cab, telling both her and John to get their own, she found herself hurt by the fact he was so closed off and distant from everything.

John looked at her again.

"I'm fine," She snapped before he had the chance to ask. He looked taken aback and she just burst into tears.

Why did everything keep going wrong?