EVERY NOW AND AGAIN, a new writer explodes on to the scene with a terrific first novel which makes it a joy to be a reviewer of crime fiction. Cathi Unsworth’s The Not Knowing (Serpent’s Tail, £7.99; offer £7.59) is the best debut I’ve read for some time. It’s very London, very hip, but in a totally unforced manner.

The reader never feels that Unsworth has done research. She has clearly lived in the milieu she describes, and talks its language. Her patch is murky, druggy Camden Town, with its out-of-fashion music played in faded pubs, its collection of outcasts and hopeful, soon to be disillusioned, youths.

Unsworth’s heroine, Diana Kemp, works for a cutting-edge magazine, Lux, which has done the last interview given by Jon Jackson, the director of the sensational gangster film Bent. It’s definitely his last because his body has been found, in a grotesque re-creation of one of the more violent scenes from the film. We are gradually drawn into Jackson’s past, which includes a brief fling with Diana, and into the warped mind of his murderer. Diana becomes involved with a young writer as ever more friends and colleagues are drawn into the aftermath of the Jackson killing. More I cannot reveal, except to say that Unsworth has a sense of pace, growing unease, menace, tension and horror that is rare in a book by a first-time author.

I have had my reservations about the last few Henning Mankell novels, so it was with pleasurable anticipation that I noticed that The Man Who Smiled (Harvill, £14.99; offer £13.49) had originally been published in 1994, but the UK rights had been unavailable — until now, when it is published in its first English translation (by Laurie Thompson). My faith in the excellence of Mankell’s earlier works was not misplaced. The Man who Smiled is one of his best. Inspector Kurt Wallander has been on compassionate leave after killing a man, in the line of duty. Depressed and drinking, he is about to quit the force when a lawyer who had approached him for help, without success, is murdered, only months after the death of his father, also a lawyer, in a suspicious road accident. Still fragile, unsure of his relationship with his colleagues after so long away, Wallander returns to work to take on the investigation. The father had been doing some legal work for a mysterious business tycoon. As Wallander nears the awful truth, more deaths are revealed and he becomes the hunted as well as the hunter.

The unlikely basis of the Bryant and May mysteries, of which Seventy Seven Clocks (Doubleday, £12.99; offer £11.69) is the third, is that there is a department of the Metropolitan Police known as the Peculiar Crimes Unit, started more than 50 years ago and still manned by its original detectives, Arthur Bryant and John May, now in their eighties. The constantly squabbling geriatecs are given the mysteries that no else wants or that contain eccentric features requiring eccentric detection.

The books are witty, charming, and informed about London, but — this is important — the story-lines are vivid, tough and have a hard edge. In Seventy Seven Clocks, a gent in Edwardian garb defaces a painting in the National Gallery, and a man reading a newspaper in the lobby of the Savoy hotel drops dead, bitten by a North American water snake.

To buy books at offer prices call 0870 1608080 or visit www.timesonline.co.uk/booksfirst

Explore Books

• Book Extracts

• Book Reviews

• Books Group

• Audio Books

Times Recommends

• The 100 Best Books of the Decade
• The Times picks the 50 best paperbacks of 2009
• The conversation: James Ellroy