"Take a seat Detective, I'm sure the Kate Moon case is keeping you fairly occupied with paperwork, and you had quite a walk from the office before I picked you up."

Lestrade was dumfounded. He had no idea how this stranger could have access to the Met's top-secret casework – and he didn't even think anyone had entered this case into the official files yet. He glanced to the proffered seat. It was tall, inviting and very comfortable-looking. And it was true he was tired and worn-out, and wanted nothing more than to sink into a red velvet chair and put his feet up. Then again, he wanted to put his feet up at home, home where he could have a steaming cup of tea in his hand, a warm dinner and a telly. Here, he needed his wits.

"No thank you. You seem to know who I am, so you'll know that I have the power to arrest you. I demand an explanation. Who are you?" Lestrade's voice had acquired its harsh aggressiveness used to deal with hardened and misbehaving criminals. DI Lestrade was almost unrecognisable as the person as Greg.

"That question is quite irrelevant at this stage, Detective."

"That question is not irrelevant and that question will be answered, thank you. And follow your answer with an explanation as to why I'm here, if you'd be so kind."

The man considered him for a moment, his mouth perked up slightly.

"I am here to inquire as to the nature of your relationship with one Sherlock Holmes," he replied to the DI's words smoothly, quite unfazed.

"You haven't answered the first question. I say nothing until you tell me who you are with proof of identification. I am a senior police officer who can have you arrested under charges of kidnapping, hacking, and harassment," Lestrade threatened.

For reasons unbeknownst to Lestrade, this seemed to thoroughly amuse the stranger.

"My dear Inspector," he began, his voice turning dangerously silky, "I hold a position in the British Government so high that, among other things, I can control all of the police's arrests, I can control New Scotland Yard's computer systems, and I can control the power grid, as you have seen demonstrated tonight."

Lestrade knew it was stupid, but gave it a try anyway: "I don't believe you. I want proof. Who are you?"

The man knew he would get nowhere with the obstinate detective, and so dug in the breast pocket of his jacket for an ID.

"I am Sherlock Holmes' brother, Mycroft Holmes."

Lestrade had a brief thought about eccentric and slightly cruel parents, and the possibility of implementing a sensible baby naming law. But then glancing at Mycroft's ID, his mouth fell open into a prefect, comical 'O'. He read it again, read it once more, snatched it to check if it was a counterfeit – which it wasn't – and gave it back to Mycroft, feeling suddenly rather inferior.

"So, I will ask again," Mycroft continued, pocketing the ID. "What is the nature of your relationship with Sherlock Holmes?"

Lestrade found his voice with an added strength, as he felt he had to now assert himself even more: "Why should you want to know?"

Mycroft smiled again, that same smile Anthea had worn in the car. "You've met my brother twice Detective Inspector," Mycroft's smile slid off his face in an instant. "I constantly worry. You've seen him; he does not look after himself and thinks that looking after his own health is the epitome of dull. Watching out for him is a serious matter, as no one else, including Sherlock himself, will take on that responsibility. So I have to screen all of his contacts. Now, I shall ask one more time, and I expect either an answer or a very much unemployed ex-DI Lestrade: what is the nature of your relationship with Sherlock Holmes?"

Lestrade believed the threat whole-heartedly, but still made it clear he was standing his ground.

"I've met him twice – as you know. I don't really know much about him…"

"Are you thinking of continuing your relations?"

"Um, well, he seems like an outstanding detective, I'd like to continue work relations with him if that would be possible, and he seems in agreement –"

"But," Mycroft interrupted, "you've also developed an intense curiosity in him, one that he doesn't feed for his lack of wanting to 'let anyone in'. You'd like further affiliations, extending beyond work. Friendship affiliations?"

Lestrade paused. It was true, and Mycroft seemed to be able to get inside his head to know what he was thinking. He could probably also do that Science of Deduction thing that Sherlock liked doing, Lestrade thought. He wondered if the entire Holmes family was this strange. He wasn't sure he'd ever like to meet the patriarch of the family; he didn't know what he'd expect.

"I'm not going to bother lying to you, because you'd see right through it: yes."

Mycroft nodded, pleased that Lestrade had recognised this. But he was also a bit unnerved by Lestrade's manner as he spoke to him; the DI wasn't submitting to the lower hand and he didn't do everything Mycroft instructed. But it wasn't just that. Though initially impressed with Mycroft's position, he now seemed to disregard it, and his manner was unintimidated, something that was completely new to Mycroft. He felt slightly wrong-footed. He didn't betray that in his actions or face though, and instead affirmed his power further.

"I background checked you and your family, Gregory Lestrade," Lestrade started at this information, "and have deemed you suitable to continue to associate with my brother. Naturally, I have him monitored via an assortment of methods – bugging, cameras, CCTV, and a team assigned to watch Sherlock. I want to warn you about what you are agreeing to go into though. Sherlock is exposed to the underground battle in London. I'm sure you see it everyday. But he is personally affected. He is a part of it, and he is, in himself, another battle entirely."

"I saw pockmarks on his arm today. And he looks…sick. Does he take drugs?"

Mycroft titled his head down, but kept his eyes up and on Lestrade.

"He does not like me interfering too strongly with his affairs, but I will say that he has certain…recreational pleasures that are detrimental to him. I am very opposed to this, and have tried to ween him off these habits through rehabilitation centres, but he refuses help from me. We have a complex relationship at best. He also has certain living habits that are unsavoury, but again, help from me is completely deterred."

"Are you getting at…"

"Yes. I would offer you money to –"

"I don't need a monetary incentive to help him get on track. There's something about him that I like, I think he's very interesting. Very complex."

"Even though he was rude to you?"

"He was rude, brusque and upfront, but my instincts told me that he's hiding something."

Mycroft was nodding again.

"I think you would be very good for my brother, Inspector. It is not often – in fact, it is never – that someone meets Sherlock and takes a liking to him. I would still be willing to offer you a fee though?"

"No. Don't be ridiculous."

"Well, here is my phone number. Should you need anything from me, or need to contact me, feel free any time. If I am unavailable your call will be taken by my PA, and it will reach me with immediate priority."

Lestrade took the business card offered by Mycroft.

"Here, I'll give you my – actually, no. You have my number. You were texting me before."

Mycroft smiled his enigmatic smile. It irritated Lestrade a bit; his face was inscrutable and you never exactly sure what he was thinking. Lestrade still didn't know how Mycroft had got his number – and he wasn't sure if he wanted to find out.

"Well, I'll be off now," Lestrade bud his goodbye.

"Farewell, Detective Inspector. My PA will be waiting for you to drive you home, and I shall be in contact soon, I expect. I am very thankful towards you. And," Lestrade turned around, about to leave through the door, "good luck."

Lestrade nodded. He wondered what exactly he was getting himself into as the black car sped off once more, now, thankfully, in the direction of Lestrade's house. Caroline had one hell of a story to hear.