Did you always want to become an author?
No. I enjoyed writing stories at school, but after wanting to be an actor - and realising that I wouldn't be so great - I turned my ambitions towards teaching (qualifying with drama as a special subject from Trent Park).
It was when I wrote some stories for children in my early days of teaching - and they were published - that I dropped acting as a hobby and turned to writing.
I went on to teach for 38 years, writing in my spare time, before I became a full time writer.
How did you celebrate when your first book was published?
I didn't really celebrate the early stories, but when my first novel, The Trouble with Donovan Croft, was published by Oxford University Press in 1974 I took my family to a celebration dinner in a Chinese restaurant in Blackheath.
Since then we have always tried to do something on publication day - because it's often a big non-event otherwise. The exception was when Orchard Books launched Little Soldier in 1999 with a party at Groucho's. That was very special.
How do you decide what to write about?
It's not me who does the deciding: it's a character, an event, a sudden idea for a plot that starts things off.
Sitting trying to think of an idea for 'the next book' is a waste of time. These desperations might lead to a chapter or two, but they usually die like seed sown on stony ground.
I do other things, get on with other aspects of my life, I don't fret and up to now I haven't had to wait too long for something to hit me.
When an aunt died some years ago she left me a musical box - the workings of which gave me an idea for a thriller, which became Running Scared, a BBC TV serial first, and then one of my most successful novels. That's the kind of way it happens.
How long did it take you to write your last book?
As I write this answer, I've got lying on my desk before me the first draft of the last chapter of a book called No Way to Go which Orchard Books intend to publish next summer.
I need to deliver the book in a fortnight - which will be tight, because I will now go through the 70,000 word manuscript once again to pull everything together.
Characters and emphases change in the writing of a novel - and I began writing this novel nine months ago.
What are you working on at the moment?
Please see the last answer. Then, it's clear out the shed.
Who is your favourite author and what is your favourite book?
My favourite author is Graham Greene, and his The Power and the Glory is my favourite of his books. In children's books, Roy Browne is tops for me - although, sadly, dead now - and I consider his The White Sparrow to be his best. Browne writes like Greene, and I should be happy to write like either.
What advice do you have for budding authors?
Just write. There's too much advice flying around - just write what you want to write - but write. No one ever wrote a good story by talking it up. Do it.
Tell us a secret…
No. If it's about someone else, who would ever trust me again? And if it's about me, then you can bet I've got a very good reason for keeping it quiet.