She stood outside 221B Baker Street, her hand hesitating just before she knocked. Her black curls covering her eyes. She knew she had to do this, but she couldn't bring herself to do it. Taking a deep breath and straightening her coat she knocked. The door opened.

'Hello? Can I help?' said a male's voice.

Lyanna looked up into the eyes of a shorter blonde headed man. She inspected the way he held himself and the way he spoke. 'Army doctor' she thought to herself.

'Hi' she replied, 'I'm looking for Sherlock Holmes'.

'I'm afraid you just missed him' came the reply 'Do you have a case you want us to look at?'

'I guess you could say that' said Lyanna.

'Well, would you like to come in and talk to me about it?' replied the doctor.

'Yes please' said Lyanna.

'Come on in' he replied, opening the door wider and stepping aside so that Lyanna could get in.

'I'm John, by the way' John said, holding out his hand for Lyanna to shake. 'John Watson'.

'Nice to meet you' she replied 'I'm Lyanna'.

'Nice to meet you too Lyanna. That's an unusual name, it suits you' replied John.

'Thank you' said Lyanna.

'Come on up' said John as he walked up the stairs with Lyanna following behind.

'Take a seat' said John as he opened the door to the apartment.

Lyanna stepped inside slowly and took in her surroundings. She loved everything she saw.

'May I take your coat?' asked John.

'Oh, um, thank you' replied Lyanna as she handed John her coat.

'Wow' whispered John as he inspected the trench coat – it looked almost identical to Sherlock's.

'Tea?' asked John once he had hung up Lyanna's coat.

'Yes please' said Lyanna as she took a seat on the sofa.

John smiled as he walked into the kitchen to make the tea. He inspected Lyanna sitting on the sofa. He didn't know what it was about her but she looked very familiar.

'So, how can I help?' asked John, as he handed Lyanna her tea and sat down opposite her.

'Well you see' started Lyanna 'Since I was very little I have been living with my uncle – I never met my mum and my dad doesn't even know of my existence. And in recent years my uncle started telling me about my dad and how soon I would need to tell him my identity…'

'Okay, I'm with you so far, but what do you need us for?' asked John.

'Well you see, my uncle is Mycroft Holmes, and that means –'continued Lyanna.

'Wait!' interrupted John 'If Mycroft is your uncle, then that means…'

'Yes' replied Lyanna 'My father is none other than the great Sherlock Holmes'.

'Oh my –' replied John.

John then sat and inspected Lyanna. She had Sherlock's hair and his eyes. Not to mention his fashion sense. He smiled to himself.

'So..' started John 'Can you, urm, well, what I mean is – can you analyse people? You know, the whole deduction thing'

'Well I know you're an Army doctor, and you've been invalided home from Afghanistan. You've got a brother worried about you, but you wouldn't go to him for help, because you don't approve of him, possibly because he's an alcoholic, more likely because he recently walked out on his wife, and I know that you used to have psychosomatic limp –' replied Lyanna.

'You sound exactly like Sherlock, except like him you got the same thing wrong-' said John.

'Not brother – Sister' interrupted Lyanna.

'Wow, just wow' said John 'That amazes me and I've been living with Sherlock for ages'

Lyanna laughed.

'So Lyanna, if you don't mind me asking – how old are you?' inquired John.

'I've just turned 18' replied Lyanna with a smile.

'Ah, so a fabulous 18th party then' said John with a knowing smirk.

'No actually' replied Lyanna with a sigh 'I spent my birthday training with the secret services, I didn't even realise it was my birthday until Uncle Mycroft surprised me with cake in the evening'.

'Well that's a real shame' said John sadly 'But you've trained with the secret services? For how long?'

'Since I was 11' replied Lyanna.

'Wow… again' said John.

'Anyway, I'm not ready to tell Sherlock the truth just yet – so, do have a good cover story I could use?' asked Lyanna.

'Well' replied John 'We could do with some assistance around here. How would you like to become our assistant?'

'That would be – perfect. Thank you' replied Lyanna.

'No problem-' began John.

'JOHN!' came a voice. Then the voice burst into the room. There he was, the great Sherlock Holmes.

Lyanna and John jumped up.

'Look what I have discovered – Oh, yes can I help you?' Sherlock asked the young girl.

'Well, um, I-' began Lyanna.

'This is Lyanna' interrupted John 'She's our new assistant'.

'I don't need an assistant – I have you' replied Sherlock.

'I'm not your assistant, I'm your flat mate and friend' replied John.

'Right…' said Sherlock.

'Hi, it's nice to meet you' Lyanna directed at Sherlock.

'Recently turned 18, never met your mother. You know who your father is, but he doesn't know about you. In fact that's why you're here in London. You've been living with a family member, someone that you've grown quite close to, uncle perhaps? - Definitely from your father's side. You have got good reflexes and you are skilled with a knife and a gun. Not to mention your combat skills. You've never had many friends; in fact, you chose not to have friends. You were made fun of because of the way you dress and the way you acted. Overall, most people would say you were a bitch, when in fact you were just being honest.' Said Sherlock with a triumphant smirk.

'You're a detective, but not a private detective, a consulting detective – only one in the world, you created the job. You are a high functioning sociopath and you do not get along with your brother. You never eat or sleep when you are on a case and you drink your coffee black with two sugars. Your favorite cases are those which include serial killers. John refuses to play cluedo with you as you always suspect the victim. You play the violin, and only compose for very special occasions. You are not very well liked amongst the Scotland Yard, Lestrade is an exception. You've had a past with drugs, and you have recently given up smoking – except that you are struggling even though you won't admit it to John. You spend a lot of your time either here or at Barts morgue, where you manipulate Molly Hooper to let you use the labs. Overall, most people would say you're a psychopath, when in reality you are a high functioning sociopath.' Replied Lyanna with a smile.

John laughed, while Sherlock just stood there in shock.

'Well I believe you just kicked his arse' said John with a grin.

Lyanna laughed.

'You're hired' said Sherlock.

'Really?!' inquired Lyanna, rather excited by it.

'Of course' replied Sherlock. 'Anyway, as I was saying John, before I was – distracted...'

Lyanna smiled.

'Yes Sherlock? What have you discovered this time?' inquired John.

'Molly, Barts, too much time wasted, let's go' was Sherlock's reply.

'Do you want me to go?' inquired Lyanna.

'No, that won't be necessary. You start work tomorrow. See you then' shouted Sherlock as he walked out the door.

'Sorry about him' apologised John 'See you tomorrow Miss Holmes' he said with a wink.

'Bye' cried Lyanna as the door swung shut.

'This is going to be interesting' thought Lyanna with a smile.

Just then, her phone bleeped.

'Need you here now. MH'

'On my way. LH'

'Your car is outside. MH'

Lyanna then put her cup in the kitchen, grabbed her coat and upturned the collar. She looked round the apartment once more before shutting the door and heading down to the car waiting outside.

-The Next Day-

The next morning, Lyanna woke up at 4am. 'Well, might as well do some training as I am up' she thought as she got changed and headed down to the training platform.

After 2 hours of training, and Lyanna was just getting really into it. Mycroft interrupted.

'I thought I might find you down here' he said 'Good morning Lyanna'

'Morning Uncle Mycroft' she replied.

'Would you care for some breakfast?' he inquired.

'I would love too, but I can't' replied Lyanna.

'You cannot. Why ever not?' asked Mycroft.

'I CANNOT because I have to head over to Baker Street.' Replied Lyanna.

'You did not tell him, did you?' said Mycroft.

'No, he's not ready yet and neither am I' replied Lyanna 'John knows and he is helping'.

'You will have to tell him soon, you know' said Mycroft.

'Yes, but now is not that time Uncle' replied Lyanna as she headed towards the door. 'I really need to go and get changed, sorry about breakfast, how about dinner instead?'

'Sounds good' replied Mycroft '8pm Lyanna, don't forget' he called after her.

'I won't' she cried as the door shut behind her.

Mycroft sighed, before heading towards his office.

Lyanna then quickly got changed, grabbed her coat and hailed a taxi.

'Where too love?' asked the cabbie.

'221B Baker Street' replied Lyanna.

'Ah, off to see Sherlock Holmes are we?' replied the cabbie with a wink.

'Perhaps…' Lyanna replied as she started to zone out.