Once they made it to the museum, they asked where Soo Lin was. Upon being informed that she had resigned, they were directed to a man named Andy, and made their way over to his location.

The Chinese Antiquities Room was filled with all sorts of interesting artifacts, but Melody knew that it wasn't the time to admire them. She followed John and Sherlock over to a man who seemed to be working there.

"Andy?" John asked as they approached.

The slight man looked over at the trio and smiled. "That's me. How can I help you?"

As the three came to a halt, they stood in a row. From the center, Melody spoke up. "Hi, Andy. We're detectives. I'm Melody. This is Sherlock and John." She said, pointing to both men respectively. "We're actually here to ask you about Soo Lin. We're looking for her."

"When was the last time you saw her?" Sherlock inquired.

"Three days ago. Here, at the museum. This morning - they told me she’d resigned. Just like that. Left her work unfinished." Andy spilled.

Sherlock looked around, trying to gather information. The Empress’ mannequin; the Jade exhibition; the wall of Benefactors’ names. "What was the last thing she did - on her final afternoon?"

Andy led them to the back room where ther were tons of other artifacts. "She does this demonstration for the tourists - a tea ceremony. She’d have packed her things away and put them here." He said, opening one of the containment areas.

Melody, however, grabbed Sherlock's hand and pulled him towards a Greek marble statue. Written on the body of the statue - in yellow paint... the same Chinese death cipher they had been seeing. She looked up at the statue, wide-eyed and in mild shock. Soo Lin had recieved the same threat.

"John, I believe we have what we need. Andy, thank you." Sherlock said, Melody close behind.

John gave a nod to the museum worker and followed his partners hastily out of the museum.

"We have to get to Soo Lin Yao." Sherlock said as they walked down the street.

"If she’s still alive! That cipher means he’s planning to kill her next." Melody fussed.

"That’s why I found him in that flat -he was waiting for her."

Before Melody could react, a voice called out from behind them.

"Sherlock!"

They turned to see Raz there in a dirty hoody and trainers.

"Well, look who it is..." John trailed off.

"I’ve found something you’ll like." The younger man said, motioning for them to follow him.

They walked along the South Bank, and Mel admired the twinkling lights as they reflected in the Thames. Had it been under any other circumstances, she would have loved to simply stop and admire the view.

"Tuesday morning. All you’ve got to do is turn up and say the bag was yours." John carried on, trying to convince Raz to take the fall for his own crime.

"Can we forget about your court date?" Sherlock huffed.

They soon arrived on the South Bank, underneath the Hayward gallery. The walls were thick with graffiti - street art from hundreds of different authors.

Sherlock stared at the myriad of colours that surrounded them. "If you wanted to hide a tree then the best place to do it is a forest, wouldn’t you say? People would just walk past it, not knowing - not able to decipher the message."

"There." Raz pointed to where someone had painted a huge tag.

Underneath, barely visible, were remnants of the yellow zinc paint - just a few tantalising splashes left exposed.

"They’ve been here. That's the exact same paint!" Melody exclaimed.

"John, go up on to the railway line. Look for that same colour. If we’re going to decipher this language we’re going to need more evidence. Melody will look around the middle ground, and I'll go opposite you." Sherlock instructed.

"Where are you gonna g...?" John started, turning to see that Raz had gone again. "Could have predicted that."

Melody giggled, then skipped away, leaving John alone.

Sherlock looked on the railway line, running south and shining his torch about. It reflected off of something lying in the gutter- an empty aerosol can with bright yellow drips around the nozzle. He picked it up and sniffed the paint.

Meanwhile, John was exploring the railway tracks to the north. There were a few homeless people on cardboard beds. He picked his way past them in the gloom, trying not to look awkward and failing miserably.

"Er... ‘Scuse, can I squeeze past you?"

A homeless guy grunted - looks threatening. "This is my place."

"I just want to look at that wall."

"Can you move a little bit?"

"Five pound."

"What?"

"You want me to move. Five pound."

"OK." John agreed, digging into his pocket.

"Ten." The guy suddenly said.

"What happened to five?"

"Too quick to say ‘Yes’."

Melody's search was significantly less fruitful. The moon illuminated the graffiti covered walls, which looked grey in the light. It was extremely hard to see anything, and it was dead silent. A shiver went up her spine and she looked around, feeling as though someone was watching her.

"Hello?" She called out. No answer, of course.

Only moments later, a figure ran out of the darkness, knocking her to the ground. She cried out as the figure wrestled her for a moment, before bolting back into the night.

She was shaking and out of breath, trying her hardest to comprehend what had just occurred. She sat up and groaned, her wrist screaming at her for landing on it poorly.

She nearly screamed when another figure came running towards her.

"Melody?" John called, his flashlight shining at her.

Stupid. Why hadn't she thought to use her mobile's light?

"What are you doing on the ground? Are you alright?" He asked as she offered her good hand for him to assist her.

"Some maniac just came throughand bowled me over. I think I sprained my wrist, but I'm alright." She said, not wanting to worry him too much. "Did you find something?" She asked him.

"Yeah! Yes, I found a wall of ciphers! Let's go get Sherlock so he can see. We'll take a look at your wrist as soon as we get back home, alright?" He assured her.

She nodded and allowed him to pull her towards Sherlock's direction.

As soon as the Consulting Detective was in sight, John began calling for him. "Sherlock! Sherlock! I found it."

The man took one look at the pair and noticed Melody's arm, pulled close to her chest. "What happened?"

"Someone took me down and I hurt it. I'll be alright." She assured him.

With that, he nodded, and they were off to look at John's discovery.

They arrived to see a blank wall, painted black.

"I don’t understand. It was here." John cried out. "A few minutes ago. I saw it. A whole load of graffiti."

Sherlock reached out to touch the wall and discovered that it was wet. Black paint. "Someone didn’t want me to see it."

He grabbed John by the head - planting both his hands on his friend’s skull.

"Hey - Sherlock! What you doing?" the shorter man exclaimed.

"Shush, John. I need you to concentrate. Shut your eyes!"

"What? What for? What you doing?

Melody stood to the side, snickering and watching the scene unfold.

Sherlock clamped John's arms to his sides - spinning round with him, trying to induce a trance-like state. "I need you to maximise your visual memory. Try to picture it. Picture what you saw. Can you remember it?"

"Sure. Yeah." John said simply.

"You can remember the pattern?"

"Yes, definitely."

"How much can you remember?"

"Look, don’t worry..."

"Because the average visual memory is only sixty-two per cent accurate."

"Oh, well I remember all of it."

"Really?"

"At least I will if I can get to my pockets. I took a photograph."

In that moment, Melody burst into peals of laughter. It was an absolutely priceless moment.

Sherlock let go, allowing John to pull his phone out and show a picture to Sherlock of the new cipher.

Mel, now calmed down enough to be comprehensible when she spoke, cleared her throat. "Well, I think that's our cue to head home, yes? Come along boys. I'd quite like to get my wrist checked over and have a nice cup of tea. It's been a trying night."

She walked ahead, shoving her good hand in her coat pocket and scrunched her eyebrows. She slowly pulled out a small black object and gasped quietly, stopping in her tracks.

Sherlock and John rushed forward to see a small, black, paper lotus sitting threateningly in the palm of her hand.