The very first contact with Sherlock Holmes I remember is the Basil Rathbone movies when I was about ten - he made quite an impression! Then when I was 13 I was given a collection of the Holmes short stories - with the Sidney Paget illustrations - and I read them all at just about the same time Jeremy Brett started playing him on TV. He was exactly as I imagined Holmes, and I became utterly fascinated.

The stories have always been very important to me. I return to them time and time again, looking for different things. My father died before I got the book, and I suppose at first I was looking for a strong male figure. But I became fascinated by the way Holmes used his mind to solve problems, unlike any of the other male heroes I read about. As I got older, I was intrigued by his imperfections and faults, and how they made him a better person. The people around him - John Watson, Irene Adler, Moriarty and others - were all such strong, layered characters that I found myself wanting to know more and more about them. Conan Doyle had built up such a complete, interesting world that I found it was very easy to get involved in it, and forget the world around me.

Do you have a favourite Sherlock Holmes story?  Why that one?

That's really difficult; I can't pick one out. I love Scandal in Bohemia and Copper Beeches, both for the same reason: fascinating female characters. I loved that Irene had beat Holmes and changed his opinion of women. I like the Red-Headed League for the sheer bizarreness of the crime, and the wonderful villain. The Three Garridebs is one of my favourites, for that glimpse of the great heart behind the great brain. Stories like The Speckled Band and Adventure of the Devil's Foot I enjoy because they are so sinister and creepy and I do love a good ghost story. Hound of the Baskervilles is basically a classic Gothic horror story with added Holmes. I find it really difficult to pick just one. 

What in particular prompted you to think of Mrs. Hudson as more than a housekeeper at 221B Baker Street?

It was while I was reading The Empty House once more and I reached the part where Holmes says that Mrs Hudson is moving the wax head in the window. I've read this quite a lot of times before, but this time I suddenly stopped and thought 'she's doing WHAT?' Dr Watson is being kept out of that room: it's dangerous to be in there. If Colonel Moran sees anyone move in that room he will shoot them - and he's a big game hunter. He's used to spotting prey. But Mrs Hudson - a middle-aged woman in a bustle - is crawling around on her hands and knees moving the bust every fifteen minutes. It's implied Mrs Hudson is actually in the room when Moran starts shooting - she hands Holmes the bullet, rather coolly remarking that it has spoilt Holmes' wax head. This all seemed very unusual for a housekeeper, even one that charges a very high rent. And it's obvious that Holmes expected that she'd be able to do it - he compliments her, saying she carried it out very well.

In the Jeremy Brett version, Holmes says 'she is becoming indispensable' (and by the way, the relationship between the Rosalie Williams Mrs Hudson and Jeremy Brett Holmes has been a great influence to me - exasperated fondness on her side, and friendship, admiration, need and occasional bad temper on his).

So I went back and looked again at Mrs Hudson. She is always in the background, always there, but bits of her come out occasionally, like the moment in The Naval Treaty when she serves him curry for breakfast - I'm convinced that this is last night's meal that he didn't come home for. She must have to deal with all sorts of visitors at all hours of the day and night, as well as a tenant who shoots her wall, carries out noxious chemical experiments and charges out of the house at 5 am, no doubt expecting breakfast before he leaves, and she just copes with all it. I think she must be a remarkable woman to manage all that.

And I do believe she is the Martha in His Last Bow. (Martha, in the Bible, was a housekeeper, after all, and how many trustworthy, reliable, middle-aged women does Holmes know?) This is a woman who very calmly goes undercover into the home of a German spy for weeks, and not only is not caught, but is never once suspected, not even as she passes information onto Holmes - and she even thinks kindly of the German. 

Given all these snippets of information, I became fascinated by her - strong and kind and patient and clever and brave.

You reportedly think of yourself as both an historical novelist and a crime writer.  How do you see the two relating to each other, and strike a balance between them?

Crimes stir up human nature and bring the worst - and best - of people to the surface. When a crime is committed, it's like someone has taken a stick and stirred up a stream bed so all the mud and stones float up to the surface, and crime does the same to the stories people would rather not talk about. History tends to be told by the people in charge, who present it as they want it to be seen. However, a crime reveals abuse and dangers and hidden tales and relationships that would normally get neatly swept under the carpet. Would anyone talk about prostitution in Victorian London if they didn't investigate the Ripper murders? Or the position of abused wives and abortions if not discussing Florence Bravo? Or baby farms if not talking about Amelia Dyer?

Talking about a crime means talking about how women, the poor and the oppressed were treated - and how they fought back. It means looking at attitudes to differences in race and sexuality, and how people coped with these. It means looking at the way people behaved and why they behaved like this. It also means looking at what people did to cover up things we wouldn't be bothered by today.

Conan Doyle used his own stories to expose forced marriage and racism and the way women were controlled and the secret workings of government all under the cover of telling a good story. I don't know if he was addressing these deliberately, or just thought it would be exciting and interesting, but you can't tell a crime tale without digging beneath the surface.  

I think telling a crime story allows me to talk about the lesser known aspects of history.

Conan Doyle preferred to think of himself as an historical novelist, but was regarded principally as a detective-story writer, and was never very happy about it.  Do you sympathize with him, or think he made too much of a fuss about it?

I do feel sorry for him, he thought he was one thing but we all saw him as another! I have read his historical novels, and they're enjoyable, but lack the genius of the Holmes stories. He was a brilliant detective story writer and created characters we still love, and perhaps he'd be happy that something he created was still popular. Although, he'd probably ask rather wistfully why no-one was making a film of Brigadier Gerard.

Your novels have been called a feminist take on Baker Street.  Do you see them that way?

Yes! I'm very proud to be called a feminist, and I am definitely writing to bring forward the roles of women in these stories.

Conan Doyle's own mother was something of a feminist for her time, and argued against her son's initial desire to kill off Sherlock Holmes so he could concentrate on other writing.  Would she have championed your approach, do you think?

I hope so. She was a formidable woman. I think she is the reason there are so many strong, independent women in the Holmes stories - women like Violet Hunter, who does the majority of the investigating in The Copper Beeches, and resists (despite Watson's romantic daydreams) falling under the spell of Holmes to forge her own career. I like to think she'd approve of Mrs Hudson and Mary Watson coming out of the kitchen and insisting on living their own lives with their own voices.

You've written some Mrs. Hudson short stories in addition to the two novels so far.  Do you intend to bring out a collection of Mrs. Hudson short stories?  How do they compare to the novels, and what appeals to you about the short-story format?

I do have other short stories in mind; I just haven't had time to write them yet. It took me a while to grasp the skill of a short story: it's so totally different from a book. If a book is a painting - one of those large Frith ones - a short story is just one tiny, intricate detail. It gives me a chance to explore aspects of 221b I wouldn't have time or reason to do in a book. I'd love to bring out a collection.

Your first novel takes place in the spring of 1889, and the second that autumn.  Conan Doyle's "The Final Problem," with the death of Sherlock Holmes, took place in 1891, and when Holmes returned to life in "The Empty House," it was 1893, and Dr. Watson was now a widower, moving back into Baker Street.  How will this affect your series?

It was a very deliberate choice to set my books at that time - I don't want to say too much, for fear of spoilers! But as the events of The Final Problem draw closer, the stories of Mrs Hudson and Sherlock Holmes become intertwined, so their separate cases end up having a massive effect on each other. I'm having so much fun writing these books, and the interaction between Sherlock, John, Mrs Hudson and Mary as I weave my story around Conan Doyle's. It's safe to say that the events of The Final Problem and afterwards are a huge event for Mrs Hudson and Mary - not just as onlookers, but as participants. There, I hope that's tempting without giving too much away!

Your novels seem to have considerable motion picture or television potential.  What's the likely future of that?

I know the TV rights have been optioned and there are talks going on, and a script has been written. That's as much as I can say right now.

Who's your favourite movie/tv Sherlock Holmes?  Are there specific actresses today you'd like to see play Mrs. Hudson and Mary Morstan Watson?

I think Jeremy Brett is my favourite, although I do have a sneaky fondness for Basil Rathbone's Holmes. I really enjoy Johnny Lee Miller's vulnerable Holmes, too, and I love the Holmes/Watson relationship in the BBC Sherlock and Guy Ritchie's films. And I love the relationship between Holmes and Mrs Hudson in the BBC Sherlock - Una Stubbs is wonderful.

As for my Mrs Hudson, it's difficult to say. Most people suggest Olivia Colman - who is, of course, always wonderful. Alison Steadman has been suggested, I think Finty Williams would be good, but everyone seems to have different ideas of what Mrs Hudson looks like.  I want whoever plays her to not be glamorous. As for Mary, I think Myanna Buring would be perfect.