Disclaimer: The case was stolen from the movie Untraceable, and so was the computer speech.
When Sherlock and John entered Lestrade's office, the DI wasn't alone; he was with a man in his early thirties Sherlock had never seen before. He was wearing brown trousers, a thin slice of neon yellow underwear visible over the waistband, and an extremely tight white shirt with a plunging V-neck. Not the kind of person who was usually spotted in Scotland Yard, let alone Lestrade's office. The DI looked up at Sherlock, and he frowned when he realised he wasn't alone.
"Who's he?" he asked.
"Doctor John Watson," Sherlock answered before adding, "he's with me."
"What do you mean he's with you? This isn't a social event; you're not allowed a guest!" Lestrade said.
"I said he's with me," Sherlock insisted, "are you going to be difficult or are you going to tell me what's going on?"
For a moment, Lestrade seemed torn between the urge to push the issue and the need to brief Sherlock on the recent events. Finally, the latter won, and Lestrade sighed heavily.
"Oh, alright. Sherlock, this is Jim Moriarty; he works for the Police Central e-crime Unit. Jim, this is Sherlock Holmes, the man I told you about," Lestrade said, and Jim smiled, extending a hand that Sherlock shook briefly.
"Sherlock Holmes! What a pleasure to finally meet you, I've heard so much about you!" Jim exclaimed, but Sherlock barely looked at him.
"Lestrade?" Sherlock asked with a raised eyebrow.
Looking weary, Lestrade turned his laptop around so Sherlock and John could get a good look at the website he and Jim had been watching before. The layout was terribly simple, just a black background with a video feed in the middle. On the top of the site, the name of the website was written in bright letters: Watch Me Kill. Under the video feed, there was a counter showing 532 active users. Even if the layout had been more elaborate, it wouldn't have been enough to distract them from what was happening in the middle of the screen.
A gagged man was hanging upside down from the ceiling, struggling. They couldn't see his hands, but from the way he was moving, it was obvious they were bound together and tied to something on the floor. He was somewhere dark, but some light came in from a single high window, which meant he was probably held in a basement.
"Is it real?" Sherlock asked, his eyes never leaving the computer screen.
"Unfortunately, it is," Lestrade confirmed before looking at Jim, gesturing for him to continue.
"The website has been up for about two weeks now, it was brought to the PCeU's attention because someone was killing animals and showing off online. He did it just like he's doing it now: a cat or dog tied to the ceiling by its back paws, and to the floor by its front paws. There was also a counter and as soon as it reached a certain number, a higher one each time as he gathered followers, the animal was killed."
"What does he do with them?" Sherlock asked.
"When enough people are watching, an arrow is fired from a crossbow aimed at the animal's heart. Well, I say animal…. It was sickening enough when he was killing animals, but now it seems like he's moved on to killing people," Jim replied.
"Are you sure it's streaming live?" Sherlock asked.
"Yes," Jim said, "can you see the window right there?" he added, leaning over Sherlock's shoulder to point at the screen. "We studied the light and weather pattern, and although we can't be totally certain, we believe this house is, if not directly in London, very close to it."
"Good to know your department isn't completely incompetent. I assume you tried to shut the site down?" Sherlock curtly asked.
"Closing the site won't work, the IP changes constantly, each new address is an exploited server that's running a mirror of the site. The site's name server uses a low TTL – that's time to live – so the computer constantly queries the name server's record. That's how it gives you a new address," Jim explained.
He seemed particularly smug. After spending so much time in the lowest floor of Scotland Yard and working with very few people, he now looked like a kid who got to show off his toys. Sherlock groaned, and he turned to look at John. The doctor looked puzzled; he probably hadn't understood a word Jim had said.
"There are thousands of exploited servers on the Internet; he won't run out anytime soon," Sherlock said as an explanation, and John nodded.
"He's accessing these machines so quickly, he's got to be running his own botnet. We are blocking the IPs, but every time we shut one down, a new mirror pops up. It's infuriating," Jim said with a shy apologetic smile directed at Sherlock.
"Sherlock, I'll need everything you can tell me from the video. We need to find that basement and stop him before that poor bastard dies," Lestrade said, and Sherlock squinted at the screen, John doing the same beside him.
"There's not much to tell. From the timbers, I'd say the house was built in the eighties."
"Anything else?" Lestrade asked, and before Sherlock could answer, Sergeant Sally Donovan entered the room and everyone turned to look at her. Her cheeks were flushed as if she had been running, and she was clutching a cell phone in her right hand.
"Found out who he is," she announced, and Lestrade immediately got up.
"Who?" he asked.
"Peter Howarth from London. He's a bartender at Beduin, he was working on Saturday, off on Sunday, but he didn't come in today. His wife claims he left for work at 15:30 for his shift beginning at 16:00, but according to his boss, he never arrived."
Lestrade quickly got out of his office, ordering his team to start moving; they were to divide into two squads, the first one would go to Howarth's house while the second one would visit the Beduin pub. There was a lot of activity while the policemen grabbed their things and got ready to leave, but soon enough only Sherlock, John, and Jim were left. Before leaving with everyone else, Lestrade looked through the doorway.
"Jim, back to your department. Sherlock, if you find that house, I may have to marry you," the DI said as he hurried out of his office.
"That's not an incentive," Sherlock shouted after Lestrade, but he didn't look back, and soon he was out of his sight, running after his team.
Jim, however, remained in the office, fidgeting slightly beside Sherlock. A few times, he looked as though he was about to talk, but he kept looking at Sherlock with his mouth agape. When he finally talked, it was in an almost quivering voice.
"So, we're bound to run into each other again if you're on the case. Sherlock Holmes on the case, that's bad news for the bad guy, right?"
Sherlock didn't answer; he just kept staring at the computer screen where the man was struggling against his restraints. Jim didn't seem bothered by Sherlock's silent treatment; he continued to watch Sherlock for another minute before finally making his way to the door.
"Goodbye, Sherlock Holmes," he said before leaving.
"That was strange," John said once Jim was out of sight.
"Yes, he was attracted to me," Sherlock said distractedly, still deep in thoughts as he watched the man on the screen.
"He was?" John asked. "He had a disturbing way of showing it."
"He slipped his phone number into my pocket when he leaned over me to watch the screen. A bold move, albeit not a very creative one," he said as he got up to rummage through Lestrade's drawers. Then, he turned to John, and he announced that they were leaving to do some research.
"What kind of research?" John asked.
"Lestrade's team will interrogate the family and co-workers, so at least we won't have to bother ourselves with tedious human interactions. We'll list the possible routes he could've taken to work, and we'll look for data. I'll just need his address," Sherlock said as he took his BlackBerry out of his pocket and started typing deftly.
"There," he said as he showed John the screen of his phone; it was the website with Peter Howarth's contact details.
"It's about ten minutes away from here. I know it's not ideal to look in the dark, but if there are signs of a struggle, I should be able to spot them. Come, John," he said, and together they left Scotland Yard.
For the bigger part of the evening, they prowled the streets between Howarth's house and the Beduin pub, looking for anything suspicious. Sherlock used a torch he had stolen (borrowed) from Lestrade's office to light up the way. While they were looking, Sherlock remained acutely aware of John's presence at his side. It was very different from what he was used to; not roaming the streets while looking for clues, he was used to that, what he wasn't used to was someone beside him at whom he could talk (because let's be honest, Sherlock did most of the talking). John always followed, even if they made several round trips to explore all the probable routes, he never complained about his leg, but the limp remained, albeit inconsistently.
Sherlock looked at everything. He searched the streets and looked for suspicious tyre marks, he looked for unnatural footprints in the sand, for grass ruffled in a particular pattern, or curious neighbours looking too enthusiastically out the window. All the while, John inquired about what they were looking for, and he tried his best to observe, sometimes pointing out things he thought Sherlock might want to take a closer look at. Sherlock was surprised to find that he was weirdly touched by John's enthusiasm; of course everything he pointed out was irrelevant, but Sherlock always felt the urge to grin stupidly every time he heard John say, "Sherlock, have you seen this?". Just because he knew it would make John light up with pride, Sherlock picked up a cigarette butt he knew had nothing to do with the case, but that John had shown him.
It was almost two in the morning when they got back to Sherlock's flat. As soon as they were there, Sherlock grabbed his laptop and opened his Internet browser to check the Watch Me Kill website. Peter Howarth was still alive and as well as he could be. He was still hanging from the ceiling, his wrists and ankles were still bound, but he wasn't struggling as much, he looked exhausted. Sherlock sat in his favourite chair, in his favourite thinking pose, with his laptop on his thighs. He needed to cogitate, to observe.
Sherlock was aware of John making tea in the kitchen, and of him carefully putting a steaming cup on the armrest of the leather chair. When John told him that he was staying on the sofa in case he needed his help, Sherlock brushed him off with a wave of his hand. For the following hour, he pictured the few pieces of the puzzle he had, shuffling them and trying to assemble them in different ways in hopes of deciphering something he hadn't noticed before. On his laptop screen, Peter Howarth was trying to keep his head raised towards his chest, but his face was getting considerably redder, and he seemed on the verge of passing out. Yet, he was still alive. Under the video feed, the counter showed that the number of viewers had almost doubled.
When Sherlock emerged from his trance-like thinking state, he realised that John had fallen asleep on the sofa at some point. He looked peaceful, content, and Sherlock spent several minutes just looking at him, trying not to picture him asleep in Mycroft's gargantuan bed. Moving carefully in order not to wake him up, Sherlock went to his bedroom, picked up his duvet, and covered John with it. John shifted in his sleep and murmured something that sounded a lot like 'camel', and Sherlock, smiling a little, resumed working on the case.