When Greg Lestrade got back to the table carrying two packets of crisps and a pint of water, the boy tossed his paper across to him. 'I finished your crossword,' he said.

'Bloody hell,' Greg murmured. He had been away for - what, six or seven minutes? 'How on earth did you manage that?'

The boy shrugged. 'I like puzzles,' he said, as if that explained everything. 'I've been doing cryptic crosswords since I was eight. My mother taught me.'

'I ordered you food,' Greg said, throwing him one of the packet of crisps, 'but eat those while you're waiting will you? I don't want you passing out on me.'

The boy looked at the packet of crisps and wrinkled his nose in distaste. 'Food,' he said vaguely. 'Food's boring.'

'Just stop philosophising and eat them, will you?' Greg told him, taking the packet of crisps from him, opening it and pushing it back into Sherlock's hands in exactly the same way that he would have dealt with his four year old.

To his surprise, it worked. Sherlock slighly sulkily started to eat the crisps.

'You promised to tell me about being a detective,' he said.

'So I did. What do you want to know?'

Sherlock slumped back in his chair, yawned widely and rubbed a hand across his eyes. 'God I'm tired,' he slurred. 'You'd better make it interesting or I won't be able to stay awake for much longer. Can you be a detective without being a policeman first?'

'No,' Greg Lestrade told him, 'You have to start off as a normal copper. Why? Are you interested in it as a career choice?' He tried to keep the surprise out of his voice. He couldn't see it somehow, this posh Cambridge student sitting for hours in a beaten up car outside a tower block waiting for a suspect. He looked as if he needed someone to tie his shoelaces for him. How on earth would he blend into some of the backgrounds that Greg had to pretend to be a part of?

'Not in the traditional sense of the word, no,' Sherlock replied, much to Greg's relief. 'But I told you - I like puzzles. I like the idea of solving things - solving people.'

'Be a cryptographer then,' Greg told him, 'or a scientist. Isn't that what science is all about?'

'You're not listening,' Sherlock told him, fixing him with a look that reminded Greg uncomfortably of his primary school headmistress when he had been caught fighting yet again. 'I like people - well no, actually that's incorrect, I don't like people, but I find them fascinating. What goes on in their tiny lives, how their funny little brains work, what makes them do the things that they do. That's what I want to work with. Not just dull equations, although chemistry is fascinating too, in it's own way.

'What about forensic science?' Greg suggested intrigued. 'That gives you the science and the crime.' And wouldn't require you to communicate with people, he wanted to say, but decided that now was not the time to point out Sherlock's lack of social skills. He hated to think about the effect that he would have on a witness, especially if they were already upset. And if they weren't, then he suspected that they almost certainly would be once Sherlock Holmes had finished with them

'I did a stint in a forensics lab last summer,' Sherlock said, with a dismissive wave of his hand. 'The science is - fascinating, but it's not enough. I don't want to work for somebody else, I want to solve the problems, the crimes, myself.'

'Well you can't do both.'

'Why not?'

'So you want to be a sort of one man detective and forensics expert,' Greg said slowly.

'Why not?' Sherlock retorted, his eyes narrowing as he contemplated Greg's reaction.

He enjoys making people feel uncomfortable, Greg thought, no not uncomfortable exactly, he likes shaking up their world view, making them look at things in a different way.'

'Because that job simply doesn't exist. You can't do both,' he told him.'

'Not in the police force, no, but just because a job doesn't exist doesn't mean that you can't do it,' Sherlock said nonchalantly.

'As what - a private detective? They don't get access to crime scenes and evidence,' The boy couldn't seriously think that this was a career option, surely. Was he really so arrogant that he thought that he could invent his own job?

'I was thinking more of a consultive role. The police do use external consultants don't they? When they need their expertise.'

'Not generally for crime scenes, no,' Greg said with an edge of sarcasm.

'Why not?' Sherlock asked.

'Because - look, it's not all about cryptic crosswords, you know,' Greg said, as the barmaid brought over a huge plate of sandwiches and deposited them in the middle of the table. 'What makes you think that you'd be good at solving crimes anyway?'

'Try me,' Sherlock said.

'What do you mean, 'Try me,''Greg asked, his irritation increasing as he picked up a sandwich and began to eat.

'I mean, tell me about a crime that you've investigated recently, tell me what happened and what you found, and I'll tell you how I would have got you your man.'

'I can't tell you about cases,' Greg spluttered through a mouthful of beef and horseradish.

'Tell me about old ones that have been through the court then,' Sherlock said, shaking his head as Greg pushed the plate of sandwiches across to him.

Greg sighed. 'Okay, I'll do you a deal. You eat, and for each sandwich that you feed into that skinny body of yours, I'll give you one detail about a case.'

'Done,' Sherlock said, as he picked up a sandwich and began to eat.

...

The plate of sandwiches somehow emptied itself, Sherlock eating almost absent mindedly as he quizzed Greg about cold cases, and came up with some astounding theories. Some were astoundingly brilliant, and some astoundingly ridiculous, but Greg had to admit that he was impressed. This boy's brain worked in an entirely different way to the majority of policeman, who plodded along straight lines. Sherlock's brain went off at odd tangents, but eventually, often after several false starts, he worked it out. Greg even threw in a case which they had shelved months ago due to lack of evidence, without letting Sherlock know what it was, and Sherlock came up with an interesting twist on the interpretation of event, which Greg found both plausible and intriguing. He might have to have another look at that case when he got back to work, see if Sherlock's theory fitted.

Sherlock had a partial view of the main bar from where he was sitting, and saw Mycroft's stiff-backed figure walking into the pub before Lestrade did. Greg knew though from Sherlock's reaction. He moved suddenly from his previously slouched and relaxed posture, sitting bolt upright in his chair, almost as if bracing himself for an attack, and Greg turned round slightly to see Mycroft Holmes approaching.

'Sherlock,' he said with a nod. 'I see that you've met Detective Sergeant Lestrade,' but Sherlock just stood up, and picked up his coat.

'Let's go,' he said bluntly, then, walking ahead of Mycroft towards the door as Mycroft briefly paused to shake Lestrade's hand and thank him, he turned and fixing Greg Lestrade with his piercing blue gaze said, 'I could help, you know. You just have to ask,' and then he was gone, leaving Greg Lestrade staring open mouthed after the two Holmes brothers as they walked in silence out of the pub. What a extraordinary pair of characters.

A long, low black Bentley was waiting outside the main door. Wolfson, the family's chauffeur leapt out of his seat to open the door for first Sherlock, and then Mycroft, before getting in himself and driving away, sliding the privacy screen across without being asked to allow the brothers to talk.

'Don't,' Sherlock said bluntly as soon as the car was in motion.

'Don't what?' Mycroft asked, crisply.

'I don't want to hear it, Mycroft. I'm aware that it was a stupid thing to do. I'm aware that you're disappointed in me, and I'm aware that I've let you down - again; now can you just shut the fuck up and let me sleep please?'

They sat in silence for a while, Sherlock closing his eyes and trying to let the smooth swaying of the car lull him to sleep, when Mycroft said quietly. 'You could have phoned me, you know. I would have come to get you.'

'And said what?' Sherlock snapped, eyes open again, 'that I've screwed up again? That I need rescuing - again?'

Mycroft sighed. 'Why is it so impossible for you to believe that I want what is best for you?'

'No, you want what you think is best for me - and for you. There's a difference.'

'Sherlock,' Mycroft said, warningly.

'Fuck off, Mycroft,' Sherlock snapped, 'I'm too tired for a lecture. Just let me sleep, before I say something that I almost certainly won't regret.'

He closed his eyes again, and there was silence, then he heard Mycroft rap on the screen, the murmur of voices, then the car slowed, stopped and Mycroft was getting out of his seat to take up the front passenger seat. He heard the sound of the car boot opening briefly, and then surprisingly his own door opened, and a blanket was placed over him. He realised that he had been shivering inside his coat with the come-down from the early drugs. He opened his eyes in surprise and Wolfson winked at him and handed him a pillow. 'Might as well be comfortable, sir,' he said as he closed the door again.

Gratefully, Sherlock unclipped his seat belt and stretched out on the back seat with the blanket and the pillow, and slept.

After what felt like only a few minutes, he heard the familiar crunch of car tyres on gravel, and scrambled to a seating position as the car came to a stop outside the house. He was surprised. He had assumed that Mycroft would have taken him straight to a rehab facility, not here; but this was better, this was easier.

'It's just for one night,' Mycroft told him bluntly as he stumbled out of the car. 'They won't take you for rehab until you're sober. We'll head over there first thing in the morning. In the meantime, I don't want you leaving your room apart from to go to the bathroom. If you need anything, ring the bell and the servants will bring you what you need. I'll have a tray of food sent up to your room, but I don't want you wandering around the house.'

'Fine,' Sherlock muttered grumpily, as he headed straight up the sweeping main stairs and towards his room.

His room had obviously been made up for him during their journey down. Clean, tidy, with crisp sheets on the bed, cushions artfully arranged on top. He had never seen the point of cushions on beds. That was what pillows were for surely. Cushions, from what he could see, existed only to throw on the floor in the evening, and be picked up again by the maid in the morning. Or occasionally to be thrown at Mycroft's head when he was being particularly annoying.

Without even stopping to remove his shoes, he threw himself onto the bed, suddenly exhausted. He was dimly aware of someone removing his shoes later, and throwing a blanket over him. Mycroft? Surely not. His bedside light was switched on, the main light switched off and he slid back into sleep.