Hello, my name is Amicus Crispus and I am one of Sherlock's oldest friends. And I do mean that literally since I died in Sussex in the year 44 AD. You see, before I had the honour of being Sherlock's skull I was a Centurion under the command of Aulus Plautius. So yeah, I had been dead for over a thousand years before little Sherlock dug me up quite by accident in his quest for pirate treasure. He promptly christened me 'Billy' and made me his First Mate. If he carried a Roman Gladius instead of a pirate's Cutlass, well, I'll never tell anyone.

Sherlock and I have seldom been apart since. At first, he kept me hidden in his tree house cum pirate ship. But, eventually everyone became accustomed to seeing him carry around a skull with an eyepatch and I was moved to the shelf in his bedroom. That was when he started the habit of talking to me when no one else was in. Not that I minded, being a skull is incredibly boring.

When he turned thirteen and was sent to Harrow, we were briefly separated. His Mum and Dad argued that he was too old to need an imaginary friend. Come the start of next term I was smuggled into the dormitory in true pirate fashion. After all, we had had lots of practice at smuggling. I was glad I was there for Sherlock because fitting in was difficult for him to do and he became bored easily. Fortunately, several of his professors saw his potential and offered him outlets for his genius, everything from advanced chemistry and physics projects to fencing and martial arts lessons.

Despite the rough start, Sherlock muddled through and still graduated at the top of his class. Once school was over he prepared to spend his gap year abroad. His Mum knew a professor at a Florida university and arranged for Sherlock to attend a summer workshop for young adults interested in becoming forensic scientists. As busy as his schedule was, Sherlock still found time to slip away and explore Miami. That was the first time I met Martha Hudson.

Time passes as it always does and soon enough uni started up. This time, no one batted an eye when Sherlock tucked me under his arm and started up the steps to our new home away from home. Though he was older, nothing really changed, he would still talk to me about how everyone was an idiot and they all hated him. I knew his propensity to speak about what others preferred to keep hidden made him the target of ridicule and abuse. He went through three roommates that year.

The next year was not all that different. Sherlock had a new roommate about every three and a half weeks. No one could stand him much longer than that, what with the impromptu violin serenades at half past three in the morning and the deductions. The House Matron was about to give up and leave Sherlock in a room to himself, despite the shortage of space that term, when Victor Trevor stepped in and volunteered. He was a godsend, or so I thought at first.

Victor truly seemed to like Sherlock. He didn't mind the experiments or Sherlock's sharp tongue. In fact, I seem to remember he was quite fond of sitting in the canteen and prompting Sherlock to make deductions about the other students. We all were happy Sherlock finally had a friend, a living one, that is… until Victor introduced Sherlock to the drugs.

After the first overdose, Victor was invited to take a ride in one of Mycroft's black cars and have a little chat. The second overdose, well, Mycroft had Victor transferred out before Sherlock got out of hospital. Dad shook his head, Mummy cried, Mycroft fumed and I just listened.

I was the only one he would talk to for the longest time. It was hard, but Sherlock managed to get his act together and actually stayed sober until he graduated. We thought the demon had been vanquished, but three months after graduation, I yelled and screamed for help as my friend seized on the rug of the Montague Street flat. No one was able to hear me, but when I managed to rock myself off the shelf and crash into the floor, Mr Patel in the flat below came up to check on the sound and called the ambulance that saved Sherlock. If you look close at my parietal bone you can see a crack running perpendicular to the suture line that resulted from the impact. It was well worth it to have saved my friend.

We had a lot of ups and downs over the next few years. Sherlock couldn't quite stay sober for long at a time. Dad pleaded. Mummy begged. Mycroft threatened. Sherlock made a list. I listened and hoped it was enough.

It wasn't. Three years, one overdose, and one suicide attempt later something changed. Sherlock wandered through a crime scene while he was high. The next morning as Mycroft was paying the fine, a young Detective Sargeant asked Sherlock if he meant what he said about the killer being the upstairs neighbour. Sherlock assured him he was not wrong. It was better from then on. The overdoses stopped and the drug use got less frequent. I still worried about him, but he seemed to be on a more even keel if you will pardon the nautically derived idiom.

He continues to get bored. Now, instead of shooting up, he defies orders and takes off after criminals alone instead of waiting for backup. It's still suicidal behaviour. It's just not obvious like the drugs were.

He still talks to me. He rants on how incompetent the police are, how they overlook the simplest of details. He tells me he wishes I could accompany him on a case and see for myself. I wish I could if only to watch his back for him.

I got a surprise the other day. Sherlock told me we were moving. Mr Caswell is selling the building and we have to move. It's fine, though, Sherlock has a new place secured already. It will be good to see Mrs Hudson again.

I won't worry as much with Mrs Hudson living downstairs. She came up this morning and brought him tea and toast. She made him eat and prodded him to get up when he had been sitting in one spot and staring down a microscope too long. Strangely, he listened to her. I just wish he had someone to watch his back when he goes out. I would if I had legs, but alas, I do not.

He said he ran into Mike today. Apparently, he mentioned to him that he was looking for a flatmate. Huh, that is new. Maybe he finally got tired of me not answering him and wants to try living with a real living person. I can't wait to see how this goes.

"That's a skull," the man with the cane says.

Sherlock replies that I am a friend and I want to groan. So much for appearing normal. Oh wait, Dr Watson doesn't seem to be put off by that admission. Maybe he's different. Now he has agreed to go with Sherlock to a crime scene. He actually seems quite excited about it. That certainly is strange. Wait until Mycroft pulls him in for one of his chats. I'd like to be a fly on the wall for that conversation. Not that it would be much different from being a skull on the fireplace mantle. Sorry, I don't get to talk very often and I tend to ramble on when I do.

Wait, I think they are back. Do I hear giggling? That's unusual. No one has ever giggled with Sherlock before. Oh, Dr Watson is going to take the room upstairs. I hope he doesn't get scared away by the pretend drugs bust.

It's three in the morning and the boys stumble in smelling of Dim Sum and Sake. I've not seen Sherlock this happy since we played pirates in that wooded glen so long ago. Dr Watson seems happy too, and he's not using his cane anymore. Sherlock whispered to me that the limp was psychosomatic. He must have been right.

I think this friendship might just work out. Well, now that I don't have to watch over Sherlock I think I might just take a nap, I haven't had one in one thousand nine hundred and sixty-six years. I wonder if I pop down to Mrs Hudson's tomorrow if she will dust my cranium. It does relax me so. (Yawn)