It was a chilly, damp morning in London as Sherlock stood looking out of the window of 221b Baker Street. He was waiting for news on his brother's case. He'd followed the clues and was sure who the culprit was he just needed to know where to find him.

John was quietly reading the morning paper. He glanced up at Sherlock. He could tell he was getting impatient. Waiting wasn't in Sherlock's nature he thought. He smiled as he watched his friend tapping his fingers on the desk. "You OK Sherlock?" he asked.

"Hm?" Sherlock turned looking distracted. John just smiled and went back to the paper. A few seconds later a cry of delight startled John as Sherlock walked over to his chair and sat down a pleased look on his face.

"You expecting someone?" John asked when he heard a knock on the door.

"Oh yes" Sherlock answered with a smirk "This should wrap Mycroft's case up nicely." Mycroft had given his little brother the case a few days ago after a highly important memory stick had gone missing from a certain government official and the perpetrator was now within Sherlock's grasp.

As Mrs Hudson showed a scruffy young man into the room she looked a little worried "Sherlock this gentleman says he's here to see you."

"Yes thank you Mrs Hudson." Sherlock replied waving her away.

John folded the newspaper, placed it on the table and waited to hear what news this homeless network member had to offer. The man gave a scruffy piece of paper to Sherlock but said nothing. Sherlock examined it. "Hm thank you" he muttered as he gave the man £10.

The man stood there for a few seconds unsure what to do. He looked at John who just shrugged and then he asked "I'll go then shall I?"

"Yes that's fine." Sherlock replied. The man turned and left still looking somewhat confused.

John sat looking expectantly at Sherlock for a few moments but he made no attempt to explain the note. Then suddenly he sprang from his chair and cried excitedly "Come on then John we have a criminal to catch."

Before John could even get up from his seat Sherlock had his coat on and was waiting for him by the door. John grabbed his gun from the drawer and his coat off the hook. He put on his coat and put the gun in his pocket as he hurried down the stairs after his friend. "Where are we going?" he asked.

"For a nice little walk by the river." Sherlock replied looking over his shoulder at a rather bemused John.

Once settled in a cab Sherlock finally explained that the note was giving him details as to the thief's possible whereabouts. "I knew he'd want to sell the memory stick pretty quickly, it's too dangerous to hold in your possession for long. So my homeless network have been listening out for any deals going down in the area and this is what they've come up with." he passed the note to John. "Of course it might not be the right deal but it's worth checking out." As the cab drove past an alley that led towards the river Sherlock added "Just here is fine thanks." and the cab driver pulled over.

John and Sherlock exited the cab, paid the driver and then walked quietly down the alley sticking to the shadows so as not to alert anyone to their presence. It wasn't long before they heard voices. They stood motionless, with their backs against the wall trying to hear what was being said. Sherlock couldn't make out if these were the people he was after, he needed to get closer. He cautiously moved forward. "Sherlock" whispered John "What are you doing?" Sherlock just looked back and waved his hand to quieten his friend.

As Sherlock moved slowly towards the group of people he could see the memory stick in the hand of a tall, thin man with dark hair. Sherlock turned to give John a nod to confirm they needed to make a move when he caught the lid of a rubbish bin with his coat. The lid clattered to the floor and the group of people scattered in all directions. Two large men pushed hurriedly past Sherlock and John but the man Sherlock was interested in was heading in the opposite direction.

Sherlock regained his footing and hurried off after the man with the memory stick. He couldn't lose him now, Mycroft would never let him hear the end of it. John raced after Sherlock while trying to pull his phone from his pocket. He needed to call Mycroft and get some backup in case things got ugly.

John watched as Sherlock continued to chase the tall, thin man in front of him. He knew he was falling slightly behind but he needed to tell Mycroft where they were. He was desperately trying to keep his friend within sight and it wasn't working.

"Mycroft" John gasped "We have your thief in sight. We could do with some back up."

"I'm hardly he police." Mycroft replied. "What do you want me to do?"

"I don't know." John yelled frustratedly "You told us this was a highly sensitive case. I didn't think you'd want me just dialling 999 for assistance."

"I'm sure DI Lestrade can be relied upon for his discretion" Mycroft snapped back.

"Mycroft, I haven't got time for this. I'm losing sight of Sherlock while I'm talking to you. I need to catch up."

"Oh very well" Mycroft sighed. "Tell me where you are and I'll sort out Lestrade."

While John was talking Sherlock was closing the gap on the suspect. They were coming to the end of the alley and the only way out was to climb the metalwork that led up onto the bridge. The man came to a halt and glanced around quickly. Sherlock was almost upon him now. "There's no escape you know." Sherlock told him as he walked towards him. "Just hand the memory stick over. I know you have it."

The man made a sudden decision and was soon climbing and swinging himself up onto the thick metal ledge. As Sherlock followed suit the man ran along the railings and headed for the bridge over the river.

They ran precariously over the metalwork on the side of the bridge. Sherlock could see the River Thames below them now. He could see the man was almost at a point where he could jump on to the bridge and disappear in the crowd. He couldn't let that happen. "Wait!" Sherlock yelled trying to get the man's attention. Anything to slow him down. Just before the man jumped into the mass of people he turned, looked at Sherlock and threw a small black something towards him. Then he was gone.

Sherlock recognised the memory stick immediately. He grabbed for it but in the process lost his footing on the metalwork. He was falling and there was nothing he could do to stop himself. He saw the river coming towards him, he felt an immense pain in the side of his head and everything went black.