'Thud, SMACK. Thud, SMACK. Thud, SMACK.'

The incessant bounce of a rubber ball, from wall to hand and back again.

'Thud, SMACK.'

This was only interrupted when John came running up the stairs for the umpteenth time in his life in this flat, stumbling on the loose carpet at the top of the stairs, once again cursing to himself and making a mental note to get it fixed. He stared at Sherlock incredulously, and when he couldn't hold it back any more, declared

'Sherlock, what are you doing?'

'Thinking'

Normally John would have been happy for any sort of response on these occasions, for talking was a relief from the pounding, repetitive sound that Sherlock seemed to be able to make with anything he could get his hands on. Normally John would have sighed, wandered into the kitchen, complained about the lack of milk, and then settled down to his blog. Normally...

But this wasn't normal. Sherlock's voice never normally sounded so strained, so... sad. There was something about Sherlock's eyes that John hadn't seen in a long time. This definitely wasn't normal. John realized this, and rushed to Sherlock's feet.

'Sherlock, what's wrong? Are you ill? Sherlock tell me what the matter is, I'm a doctor, I can help. Is it your brother?'

Sherlock sat there in silence for a moment, a moment that felt like, well, a long time. He looked deep into John's eyes, feeling the soft ache that pulled at the edge of his heart, knowing he must not show it on his face. He dropped the ball and John watched it bounce twice and then proceed to roll under the sofa. At least that was the end of that. Sherlock sat up from his lazy, slouched position, put his head on one hand and motioned in the direction of the desk where books and documents were balanced precariously into small mountains. Upon the small peak nearest to the wall lay an unusual royal blue envelope, crisp and dark like a new leaf, but hardly as welcoming.

'What... that's not from the surgery is it? Sherlock, I...'

'John, for god's sake, I'm not ill!'

Sherlock bursts out from his shell, verbally lashing out at John in a way that John had almost become accustomed to when said something that Sherlock considered 'idiotic'. Sherlock stood up, and with the most grace and dignity he could in his clearly beaten shape, he walked over the the imposing piece of stationary and stared down at it until he picked it up and turned it over in his hands. The face of it is littered with a thousand stamps from obscure places, most of which he was pretty sure weren't from Earth. Though, Sherlock thought, that made sense...

He walked over to where John was sitting, carefully slit the envelope and showed John the contents. John recited the date and grid reference, and looked up at Sherlock. The man stared back, his eyes hollow and black.

'Who is this from?'

'A friend'

'I thought you didn't have friends' John retorted jokily, trying to lighten up the mood.

'A friend' Sherlock repeated, without breaking composure.