Another fruitless all night stake-out means another exhausted early morning trek across town. It's better than a cab. We'd fall asleep in a cab. Anyway, Sherlock needs to walk off the frustration of another night with no rewards. I haven't really been able to talk to him. I'm not sure he'd even hear me anyway; he doesn't even seem to be able to see properly. His steps are just following mine, like a blind man behind his dog. And though it's all rather lovely that he's placing so much trust in me, I'm not sure how I feel about it. Not only is there the fact that I was never asked to be considered, but the temptation to see just where exactly he'll follow is enormous.

But that would be wrong.

And unethical.

But the shops are just opening and I do just need to make one quick stop and it's on the way and I'll bet he does it. I stop to make sure I have everything I need and he stops right alongside me like we're waiting at traffic lights. For all he knows, we are. It really does serve him right for taking advantage.

It's a detour of maybe three streets. As I anticipated, Sherlock doesn't notice a bloody thing. Until, of course, he hears a pair of sliding doors easing apart and he steps, looks about in shock like one who's just heard a gunshot. "John," he balks, sickened. "You… You tricked me."

"Don't be so dramatic. I have to pick up my Click-and-Collect today."

He peers inside without setting foot through the doors. Having been basically nocturnal this week, his eyes squint almost shut, faced with all the bright lights and yellow walls and wood floor. "My God, what hell have you led me to?"

"It's a catalogue shop," I tell him. "They have everything. You give them a number and they fetch you what you want. It's dead handy."

He nods sagely, confirming with himself, "Hell."

"Come on," I say, and take him by the sleeve. "Won't be two minutes. Anyway, you'll enjoy this."

"Oh, I doubt that."

"It's your brother's birthday at the weekend. I'm getting him the single cheapest pair of cufflinks I could find." He says nothing, drifting off again, but he doesn't have to. He likes that idea. Knew he would. "I bet you'd forgotten about that."

"What, about Mycroft's birthday? I had not. As a matter of fact I've got half his present in my inside pocket. Picked it up yesterday."

"Giftcard for Next, get himself a nice shirt?"

He almost laughs. "Return ticket for New York. He has to go for business anyway."

"And you just bought the ticket." And made me feel like an absolute bastard, well, thank you, Sherlock, that's exactly what I needed this morning. "Very practical." But I have to go through with this now that we're here, now that I've tricked him. I have to slide my sheepish way up to the jewellery counter in the corner with my Click-and-Collect number, my idea to annoy Mycroft I used to be so proud of. Sherlock follows just as blindly now that he's aware of his surroundings. I think he's trying not to see now.

So I'm waiting my turn, trying desperately to think of some way out of this. The girl in her black uniform smock is still dealing with her last customer. Before I even really start to listen, I notice that her hands are shaking. She keeps pushing back her hair, starting to look just a little bit flustered.

The customer is a short woman, very stocky, with a trace American accent. She walks with a crutch and is stabbing one sausage finger against the glass of the counter over and over.

Then I start to listen.

"You're not paying me any attention, young lady," she's saying. "I bought this from one of your stores not two hours ago, and the diamonds are falling out of it."

The young lady in question tries to explain that it's probably been a manufactural fault, and her customer laughs in her face. "Oh yeah, it got here like that. Listen to me, you work for this company, you stand by the shit you sell, okay, miss?"

This goes on. This would appear to have already been going on for some time and it goes on while we're standing there. Everything the girl tries to say is put down by the decidedly threatening woman on our side of the counter and used as the basis for another minute or so of enraged ranting. She has, I'm informed, spent thousands in this store over the years. She has never encountered such awful customer service. The jewellery girl is the single nastiest piece of work she has ever had the misfortune to come across.

"How would you know?" Sherlock said that. It's such a shock to hear him speak at all that I jump. I'm still stunned when he slides past me and continues. "She hasn't had a word in edgeways, how would you know if she was nasty or nice?"

"And who are you?" she demands, unfazed, "Her bloody manager? Because I'd tell you, I want a word with you."

"I'm sure you want dozens, but I don't work her. No, I just happen you think you're a vicious middle-aged harridan who's just beginning to get a little bit out of line."

The jewellery girl looks over at me, and I must say it's a comfort to see someone staring back, just as mystified as I am, somebody who shrugs when I shrug. Nope, sorry, no idea what he's doing. Let's find out together. She doesn't know him, so she's not half as shocked as I am. As he breathes in to continue she drapes herself over her computer monitor like he's telling her a bedtime story.

The harridan has opened her mouth to give Sherlock an argument, but of course he gets in first. That bit doesn't surprise me.

"It's the crutch, isn't it? And the fact that you're slightly deaf in the left ear, though really that doesn't excuse the tone or volume of voice you took just now. No, they leave you feeling a little bit put out, don't they? That's very unfair of you, you know, there are people with far, far greater disabilities who still manage to be perfectly functional members of society. People like you give them a really awful name. No, madam, frankly, you're not worthy of the thumbs that separate you from the average stray mutt out on that street."

She fumes, purses her lips and turns red from the neck to the hairline, "Why, I'll get my Kevin down here and-"

"Mmh," Sherlock cuts in. "Big fellow, is he? Six-four, three hundred pounds now. But he was two when you met him, and it all used to be muscle. He didn't know what he was getting into, did he? Met at a party, was it, friend's house. Then presto-pregnant and down here for the ring. That's an old story, very boring indeed… I'll bet he's a belligerent sod and all, though you wouldn't blame him quite so much. One imagines he has his reasons. By the way, those aren't diamonds falling out of your ring, they weren't sold to you as diamonds and unless someone was being wilfully intimidating they would never ever have passed for diamonds. I know that, this young lady right here knows that, so why don't you take your crutch and all your other crutches, and your fake bloody ring, and charge yourself right on out the door, hm?"

She fumes a moment longer before she flees.

"Feeling better?" I ask. I can only presume he did that to salve his own wounds, after losing out last night. A bit vicious, overall, but at least he was semi-justified. And his damsel doesn't seem to care a bit.

The shopgirl unfolds from around her till, reaches out and grabs his hand. "Are you Jesus?"

Sherlock doesn't even seem surprised, pats the hand around his and smiles, "Not quite."

"Look, I don't care who you are, but-"

He passes her hand to me, "All yours."

It's the best service I've ever gotten in any shop in my entire life. But she's always looking over my shoulder, watching him, thinking of him. Even her company loyalty falls away to offer her very best to a friend of his; when she brings out those godawful base metal cufflinks, she gives me every possible opportunity to walk away. Every 'are you sure' and 'I could show you something else', every time, I have to shake my head. By the fourth or fifth desperate exit, by the time she mutters softly to me about staff discount, even Sherlock has deigned to look round. He claps a hand to my shoulder and tells her, smiling, "Oh, he's sure." At which point it's all about gift boxes and can she wrap them for us.

Between paying and receiving my receipt, she stops to write something on the back of it.

"My number. Anything I can do for you, up to and including marriage-"

"Oh, it won't come to that, I'm sure."

Sherlock slides past me again. As he leans towards her, he reaches into his coat. "Do you work weekends?"

"Nope. I'm a nine-to-fiver."

"Want to spend a weekend in New York?"

She blushes, one hand coming up to hang on her necklace. "I beg your pardon?"

"No, not with me, no strings. Promise to do me one little favour and you can take a perfectly genuine return ticket here and now."

Again, she looks at me. Again, I can only shrug, but this time I've got something to offer. "I don't think he's joking," I can tell her. Still, she eyes him warily. She's never had a day this good in her life, you can tell.

She lingers too long. Sherlock gets bored, adds, "It's a first class ticket."

She has it out of his hand before he can so much as blink. "What's the favour?"

"You'll be seated next to a rather irritating blonde gentleman. A transatlantic flight is very long. I want you to do everything in your power to do to him what your last customer tried to do to you, and ruin everything."

Crap cufflinks still seem like an awful idea, by comparison.
***

There is no better way to forget the passing of time than to change time zones, forget entirely the onward march of years by jumping back by hours. But as Mycroft takes his seat, places the order for his in-flight meal and drinks, he becomes gradually aware of a truly awful stench. After a moment he traces it to the young lady in the next seat. By the state of her hair and face she hasn't washed for days. She sees him looking, mistakes it for interest. She gives her name as 'Chardonnay', in the broadest, brashest accent he's ever heard and quite a few decibels too loud. Holds out her hand and he takes it, out of politeness, looks on in horror as she cracks open an enormous bubble of neon purple gum…