Every great city deserves at least one paperback detective - a feisty soul who ventures into its shadowy bylanes;sneaks into the lairs of its rich and powerful denizens;and stumbles upon corpses in the unlikeliest of places. London has poet-cum-policeman Adam Dalgliesh;Chicago has wisecracking private eye, V I Warshawsi;Shanghai has earnest Inspector Chen. And now Mumbai has razor-sharp, retired policewoman Lalli LR. LR because everyone agrees that "Madam" is the Last Resort for tricky homicide cases.

The Monochrome Madonna is the third novel featuring this sometimes stern, sometimes exuberant grey-haired Maami. Once again the redoubtable Lalli curls up in her beige sofa, downs countless cups of coffee, whips up mouth-watering potato curries and rattles around the city in her old Fiat before staging a dramatic denouement. No wonder then that one of the characters compares her to "that Agatha Christie old lady".

This particular book starts in classic murder mystery style with a blood-splattered corpse. Sita, Lalli's earnest and gullible niece, receives a frantic call from a woman named Sitara, a casual acquaintance from her college days. Alarmed, she rushes to a nondescript apartment block called Kalina Sputnik and storms into the flat belonging to 'S. Shah and V. Dasgupta'. And it's in the drab living room of this 1BHK that she finds the body of a large, "recently dead" stranger.

Lalli is away on her annual jaunt. Her sidekick, Inspector Savio, too has vanished to Dehradun in pursuit of true love. And Sita is left to deal with the drugged and hysterical Sitara, her distraught husband Vinay and the suspicious police. "I have seen nameplate, " remarks Inspector Shukla about Sitara. "Anything is possible. She is not using husband's name."

Mercifully, Lalli soon returns. But rather than attempting to identify the dead stranger or verify the ugly tale in Sitara's diary, she seems preoccupied with irrelevant details: the hideous photoshopped version of Raphael's Sistine Madonna that looms over Sitara's living room;the latest in Lancome lipsticks;the colour of Sitara's toenails. Detective work, she maintains, is all about asking the right questions.

Indeed, the questions she raises are fascinating. Unfortunately, the eventual answer to this intriguing puzzle is disappointing. And the final solution is needlessly compli cated, unconvincing and rife with loose ends.

Nevertheless, the process of getting there is great fun. Kalpana Swaminathan has a sharp ear for dialogue and eye for absurdities. And the book takes us across the city to meet all manner of Mumbaikars and eavesdrop on some quintessentially Bombay babble. So there's the fluorescent college-girl who, like, can only do bimbo speak. And the ad agency boss and ecowarrior, who dresses in gunny-sack kurtas and recycled razorblade earrings, and ensures that the office chairs are fashioned out of old buckets. And, of course, the North Indian proprietor of the Fatafat Press, who moans, "For forty years I have given this city my blood and sweat and now they tell me I am not Bambaiyya!"

Admittedly, The Monochrome Madonna has its flaws. The story often goes off on tangents. The writing is sometimes cute and cluttered. And the narrator can be irritatingly goody-goody. But it is still an enormously enjoyable read. And Lalli is clearly a good "Madam" to know.