I don't care how you faked it. I want to know why.

Your character's gone through a lot of transformation. Can you talk us through some of the main things?

Well, I guess as far as he's concerned. It's been two years since he lost his best friend.

You know, his best friend died in front of his eyes, and he's had to move on or just

be depressed. I think probably part of him does still carry that depression or carry

that sadness that you do I think when you lose someone. You know, when we lost someone

very close to us, I don't think we ever quite get over it, and John will always have the

residue I think of that sadness, but he's fallen in love, and he's moved on. John was

always a bit of a ladies man. You know, he's established that he always liked the birds,

and this one he's fallen in love with, and they're going to get married. So that's a

change for him.

I think I'll surprise John. Roll up to Baker Street. Who knows? Jump out of a cake.

Baker Street. He isn't there any more. It's been two years. He's got on with his life.

What life? I've been away.

Sherlock, for an actor, it is the most dream roll. What is the best thing?

It is. It's really hard. It's really good fun getting to work with Martin Freeman and

those scripts is a joy, and yeah, I love the challenges it brings.

Now, if you were going to fake your death, what would you do, and you had a week of anonymity,

what would you do?

Oh, become a journalist. Turn the cameras around on other people, I think I'd do that

for a bit.

Really? Get behind the camera, yeah yeah. No one would know. No one would think, would they?

The terror alert has been raised to critical. Welcome to my world. An attack is coming.

What are Benedict and Martin like off camera?

They're really awful. They're just dreadful, very monosyllabic, not very nice to talk to,

quite demanding... Martin's like that at home. No, they're not. What can I say? They're fantastic.

I mean, Benedict's a dear friend, and I've lived with Martin for 13 years, so working with them both was

a joy. It really was. It's fantastic.

I was just saying to Martin. I just generally think that actors should always play with

their real other halves. I think it works. Yeah, I think it works. I mean, you know,

we get on very well. We've worked together numerous times before, and I think Mark and

Steve just thought it's an easy bet, you know? That's you're going to get that chemistry,

and I think we do have a nice chemistry. We have an ease on screen that I think is quite nice.

An attack is coming.

I need to get to know London again. Breathe it in, feel the quiver of its beating heart.

Sherlock returns New Years Day at 9 on BBC 1.