About an hour into my interview with Mark Billingham, the conversation turns to suicide. We are sitting, a little incongruously given the subject matter, in the plush Thameside offices of his publisher.
The reason for the grim discussion is Billingham's new novel, The Dying Hours, an ingenious police procedural driven by several seemingly unconnected people killing themselves. For his regular hero, Tom Thorne, there is no such thing as "seemingly unconnected", and he begins his usual dogged investigation.
"It sounds odd to say that the research into suicide was fascinating, but it was," Billingham admits.
He was astonished by how many of his preconceptions proved inaccurate. "More people kill themselves at Christmas? No they don't. Most people leave notes? No they don't.
Most people kill themselves between three and four o'clock in the morning? No they don't.
The most fascinating one of all [is] the gender split. A lot more men kill themselves than women, but a lot more women try. Men are just better at it."
I ask, somewhat tentatively, whether Billingham himself has ever considered ending it all?
He pauses. "It's certainly nothing ..." he begins before faltering. "I've never been ..." At that exact second a book (Yes, Chef by Marcus Samuelsson) swan-dives from one of the shelves on to the floor with a heavy thud. "And at that point," Billingham exclaims with a nervous chuckle, "a book threw itself off a high shelf."
It's a very Billingham moment - at once eerie and oddly lighthearted. Before he hit the best-seller charts as one of Britain's leading crime writers, Billingham was variously a stand-up comic, an actor and a scriptwriter, combining all three on a much-loved
children's show, Maid Marian and her Merry Men. Billingham's career, and indeed his life, took a sharp detour when he dreamed up his first novel, Sleepyhead, while on summer holiday in 1999.
"I take what I do hugely seriously. But I don't take myself very seriously."
And though he could doubtless spend hours elucidating the similarities between constructing the surprising punchline and the perfect plot twist, he joins the dots between comedy and crime in other ways.
"I am trying to give the best performance possible in 400 pages. I want readers to be scared, I want them to be moved. Entertainment doesn't necessarily mean something trivial, but it does mean people wanting to get to the end of a book."
Performance certainly informs Billingham's super-charged conversation - even played back at half-speed on my dictaphone, his sentences rush by faster than I can type. It is not only his mouth that is in perpetual motion. Billingham can't sit still for a second, crossing and uncrossing his legs, leaning forward and back. One minute he strains every sinew to make you laugh. For example, about the time-honoured question: why do you write?
"I have heard some novelists say, 'because if I didn't I would shrivel and die. It is my soul, the only way my heart sings.' You know, writers who want writing to sound mystical. But that's not me. I often wonder, with my hand on my heart, if The Dying Hours was made into the biggest movie franchise in history, would I pick up my pen again? Wouldn't I be happier spending the rest of my life travelling around with my wife?"
The next moment, however, Billingham is possessed by a passionate desire to make himself plainly under-stood about the darkest topics imaginable. For example, on the media obsession with violence against children. "You can't open the paper at the moment without the most horrendous stuff about child murder ... whenever people ask where I get my sick and twisted ideas from, I reply, 'just open your eyes'."
As the restrained, elegiac mood of The Dying Hours illustrates, his writing has matured over the years: a recently demoted Thorne not only confronts life in inner-city London, he faces up to ageing and even the prospect of retirement. Even his adversary is a pensioner, albeit one with a deadly gripe.
"I think it is getting older, I think it's having written 15 books, I think it's being in my early 50s, but I am suddenly less interested in crash, bang, wallop than the motor of the narrative. There's still lots of blood - that's what readers want. But what haunts me now is whether Thorne should have a kid, not whether he should have caught a killer."
After 15 books, Billingham insists that Thorne's story is far from over: he is already writing "Thorne: 12", but he does worry about pushing his hero past his sell-by date.
"You throw the kitchen sink at your early books. You put everything in there. It's like when you meet a new girlfriend or boyfriend, you tell them all your best stories. By the time you have been married for 10 years, they are crying, 'shut up!'" Billingham laughs. "What can you do?"
• The Dying Hours (Little, Brown $37.99) is out now.