PW: You described the incentive for your previous novel, Birdman, as coming from other crimes. Is that the case with The Treatment?

MH: Not things that happened to me personally, no. I guess everyone gets inspired by real-life events on some level, and there were some things that happened, though not to me specifically. But some crimes that have happened in London started the ideas ticking over. This was before pedophilia became a "hot item" in England.

PW: Given the nature of the subject matter, were there any difficulties researching this novel?

MH: Of course it was harrowing. I think the thing that affected me the most is that, probably about two-thirds of the way through writing it, a little girl in England (I don't know if it made the news in the States) went missing. I think she was missing 14 days before she was found. It was a very hot, oppressive summer, and she was in every newspaper and on everyone's mind. The opening of The Treatment deliberately echoed this. I actually stopped writing for several weeks, because I experienced an extremely uncomfortable feeling that I was responsible in some way because I'd written this book.

PW: Did you speak with child or criminal psychologists in the course of your research for The Treatment?

MH: No, I worked directly from case studies for that part.

PW: Would you say that law enforcement (or psychology) have made any strides against pedophilia in the digital age?

MH: I think most law enforcement agencies would like people to think that they are a lot more savvy about how to deal with the problem than they actually are. I'm not a computer expert, but it's my understanding that there's an incredibly long process for investigating [pedophile networks], and it's governed by the same sort of privacy laws as, say, phone tapping. It's so easy, for example, to change one's ISP, which can affect the sort of suits [search warrants] the police have to obtain to get people to divulge information.

PW:The Treatment made the number 10 slot on the London Times's bestseller list. Has the reception continued to be as rosy throughout Europe?

MH: Actually, it hasn't been released anywhere besides England for the moment; that's all in the pipeline. The Treatment hovered around the number 10 slot for a while, and Birdman reached the lists in paperback as well. I think I was very lucky.

PW: Will DI Caffery ever move beyond London in the course of his investigations?

MH: I don't know what's going to happen to Caffery. I've abandoned him for the moment. He's stuck in southeast London; some of the best of us are. I'm writing something now which might not be classified as being in the crime genre. It's more of a thriller, set in Tokyo in the late 1980s, based on personal experience.