Crash. Bang. Thud.

'Avast yeh scoundrels. I be comin' to steal yeh treasure and there's nothing you can do about it! Aye me hearties, lock the captain in the brig!'

Sherlock span around, clutching his cardboard sword and pointed it at his older brother. 'That means you Mycroft. You can't be first mate if you can't follow simple instructions.'

Mycroft glared down at the six year old from where he was trying to complete some coursework.

'Sherlock, I have no wish to be your first mate and the sooner you give up this little pirate fantasy the better. I thought you were supposed to be smart?'

'I am smart Mycroft!' Sherlock whined. 'I can tell that you had marmalade on toast for breakfast, bad idea if you ask me, plain toast is much less fattening.' Sherlock raised an eyebrow challengingly at his brother as he began to reel off his deductions. 'I know that you wore your new shoes yesterday because there's a red patch on the back of your heel, you haven't worn them in yet and from that I can deduce that you saw Gregory. He's the first friend you've ever had and you wanted to impress him. Tut tut Mycroft, isn't it you who always says caring is a crippling disadvantage?'

Mycroft huffed in annoyance but Sherlock pushed on.

'I can also tell that mother does not know about your little escapade, maybe because she doesn't approve of Gregory, more likely that she doesn't like his father who works in a leather tanning factory, the smell is still faintly clinging to your trousers, the same trousers you wore yesterday as there are scuffs on the knees from where you jumped over the garden wall to avoid mother. Anyway, mother thinks he's not good enough for you to be friends with because she doesn't approve of his father's occupation and I have absolutely no qualms with informing mother of your dubious whereabouts yesterday unless you agree to be my first mate.'

Sherlock smiled in triumph as Mycroft massaged his temples. In all honesty it was an easy victory. Maybe too easy…

Mycroft smirked making Sherlock squirm under his gaze.

'Fine, I'll play with you,' Mycroft said slowly, 'but only if I'm captain and you're first mate.'

'What makes you think I'll let you be captain? If you refuse to play with me I'll tell mummy about Gregory.'

'I know, brother mine, but if you tell mummy about Gregory, then I shall tell her about John.'

Sherlock stood stunned for a moment.

'You wouldn't dare…' he whispered, shocked.

'Oh wouldn't I?' Mycroft raised a cool calculating eyebrow. 'So I wouldn't tell mummy that you skipped school to show John round Scotland Yard? I don't even want to know how you got in there. Safe to say, mummy would not be happy.'

'How did you know we went to Scotland Yard?' Sherlock scowled at his teenage brother.

'I found Gregory's father's ID badge in your pocket,' he replied. 'You never could resist temptation, could you?'

'Fine,' Sherlock poked his tongue out, 'you can be captain.'

'Then your first job as first mate,' Mycroft announced, snatching Sherlock's sword, 'is to find your captain some cigarettes. Father has confiscated them again and I can't be bothered to go out and buy some more.'

'Aye, aye Captain,' Sherlock yelled, leaping out of Mycroft's bedroom and down the hallway. No measly cigarettes would escape the famous Sherlock Holmes!