Three months into his first tour in Afghanistan, John learned that if things were going well, some sods-law rule of the universe would make sure a catastrophe came along just to ruin it all again.

On his second tour, he learned to only smile and laugh with the other lads, never on his own, just in case there was a limited supply of the good emotions and when they reached the bottom of the jar that catastrophe was waiting to strike.

On his third, he learned to stop looking at the stars or noticing the brilliant red of the poppy fields, just so he'd have a little more time to see a young private's face with hope in his eyes.

He might tease Sherlock about not knowing the stars, but he caught himself before he could look up some nights, just in case.

.:*:.

'Sherlock!' John called, shrugging into his black coat. 'I'm going out for a bit. I've left you a list of things to do and not do with Hadrian after he gets out of the bath, alright?'

Sherlock suddenly appeared around the kitchen doorway, eyes narrowed. 'Out? Where?'

'The surgery needs me to come in for a little while,' John said, trying for a realistic mix of casually light and mildly annoyed. 'Apparently I mixed up a couple of intake forms and they want to confirm that they've got the patient records correct. I'll probably get roped into helping out with getting some of the newer records into the system while I'm there, but I'll be back this afternoon.'

If he didn't know better, John would've said Sherlock was holding back a pout. 'We're interrogating the neighbour today,' he protested.

'We can do that this evening,' John pointed out as he zipped up his coat. Snow wasn't falling yet, but frost slicked the ground and patterned the windows every morning and a sharp bite crisped the air. 'I'll be back in plenty of time, I swear. Now. List is clipped to the fridge. Make sure Harry gets lunch, yeah? Probably between one and two so he doesn't spoil his dinner? Phone in for takeaway if you can't do your usual charm Mrs Hudson into doing something up.'

Sherlock looked faintly insulted. 'I don't charm people, John. I get my way by pointing out that my way is the most logical and expedient.'

John rolled his eyes and stepped out onto the landing. 'Suuure you do. Pointing all that out while you flash your cheekbones and do that big eyes half smiley thing, making it sound like the whole world's against you.' John mimicked Sherlock's habit of dropping his chin and fluttering his eyelashes and dramatically waving his hands as he clomped down the steps to the front door. Sherlock thundered down after him.

'I do not do anything remotely-'

'Oh! I was wondering what all the noise was about.'

'Sorry, Mrs Hudson,' John apologised, as their landlady poked her head out her flat door. 'I have to go into the surgery for a while, would you mind keeping an ear out while I'm gone? I've left Sherlock a list, but...well. Any big bangs, shrieks...' He offered her that weary what can you do? It's Sherlock. smile they so often shared, and she melted.

'Of course, Doctor. Sherlock, I hope you're looking after poor Hadrian properly! He seems such a shy little boy.'

'Mrs Hudson,' Sherlock said, fluttering his hands down onto her shoulders and tilting his head down a little so he could peer up at her through his eyelashes. 'Whatever John has told you can be dismissed. I am an excellent caretaker for our dear Hadrian.' He softened his gaze and lifted one side of his lips in a weary half-smile. 'Even at mealtimes, when I have to stop myself in the middle of complicated and painstaking life-saving experiments and abandon them to cooking-'

Suddenly he stopped, and froze. Then he turned to John, who couldn't have held back his smirk if his life depended on it.

'Oh, shut up, John,' Sherlock snarled, and stormed upstairs.

John was still chuckling halfway down the block.

.:*:.

John decided to make things easy for Mycroft. First he took a left out the front door and headed south down Baker Street, because that's what Sherlock would expect to see if he really were going to the surgery; then he went left again, and headed east along Marylebone Road, because with Madame Tussauds on one side and a University of Westminster building on the other it was impossible that he wouldn't be picked up by at least a few CCTV cameras, despite the tourists and double lanes of cars. He ambled on past the Princess Grace Hospital, which had more cameras, to pick up a cup of coffee at the Crypt and Goose Cafe, which didn't seem to even have a security camera, but John didn't mind because the name made him think of Sherlock and stifle a chuckle.

To avoid going past Baker Street again he made a twenty minute loop of the Outer Circle and Rossmore Road, finally turning south again when he was far enough west and heading down Harewood to Marylebone Station. He stood out front the brick gate, sipping his coffee and feeling rather pleased with himself. He might not have a perfect map of London in his head like Sherlock did, but he knew where to wander to attract a Holmes.

Soon enough a black car pulled up and the door opened. John got in.

'Hi,' he said to the woman in the back.

She gave him a pitying smile. 'Hi,' she said, and turned back to her Blackberry.

'Right,' John muttered, clasping his hands between his knees. He tried to marshal his thoughts into line. Things had been going so impossibly well with Hadrian, and Sherlock, and work- life in general. He'd been happier for the last week than he had in half the years before he met Sherlock combined. He knew that catastrophe was hanging low over his head by now, but damn it all if he wasn't going to be ready for it.