She means business, with a warm heart. Meet Sudha Gupta, desi Miss Marple, the brisk and uber-efficient private eye with a sharp sense of humour and a sharper nose for the dark side of the lives of others. To be sure, fiction has no dearth of such detectives, but Gupta is as fascinating a character as her creator, the compelling Tamil writer Ambai, known outside her writing cloak as CS Lakshmi.

This is an interesting turn of events for Ambai's readers, and passionate fans she has many. Ambai's short fiction has always been dominated by women characters who own their stories, but this is the first time the writer has turned to crime writing and detective fiction.

Juggernaut has recently released on its app the first novella in the “Sudha Gupta Investigates” series, titled As the Day Darkens, translated from the Tamil by Gita Subramaniam. Two more novellas, each featuring a different case but the same detective, are expected over the next two months. The print version will be out at the end of the year.

There has been something of a deluge of crime fiction in Indian publishing in recent times, and practically everyone who has a desire to write seems to have a mystery up their sleeve: entrepreneurs, financial experts, bankers, journalists. In the last decade, a bunch of women investigators have emerged: Kalpana Swaminathan's Lalli, Madhumita Bhattacharyya's Reema Ray, Kishwar Desai's Simran Singh. And now we have Ambai's Sudha Gupta, a middle-aged Tamil investigator in Mumbai, her language peppered with Marathi, lover of cinnamon tea.

A different script

Long-time chronicler of women's lives and spaces, female sexuality and gender roles, Ambai may seem well-settled in her powerful literary role. But then she isn't one to be bracketed anyway, not in her writing, not in life – and so here she is at 72, trying her hand at something new. It's utterly refreshing to see her don an unusual avatar. She continues to be sensitive and lyrical in her writing, but with a tone more urgent, and a plot more complex, to suit the twists and turns of a mystery.

In As the Day Darkens, three young sisters go missing while vacationing at a resort in Madh Island, in Mumbai. The girls' parents and little brother are understandably frantic, and even as the police investigates, the reputed Sudha Gupta, who often assists the local police, gets drawn into the tragic case.

Where did the girls disappear? Were they kidnapped? Are they dead or alive? The questions keep adding up. This mystery seems all too real, like something you would read in the newspaper any given morning.

In the manner of all clever detectives, Sudha Gupta picks on seemingly unconnected strands and delves into the past to figure out the present, winding her way through the mystery with the expertise of someone who has been there, done that. It helps that the mother of the missing girls, Archana, finds it easy to confide in the amiable and gentle detective in her darkest moments, and this gives her an intimate feel of the case, as it does the reader.

Despite its brevity, the story builds and holds up well. There is the quintessential twist in the tale, a depth to its characters, a well-etched milieu, and the loose ends are nicely tied together as we go along. The narrative moves back and forth between the scene of crime and of the investigation, which keeps us on the edge and offers a nice non-linear touch.

Yet, this is a pretty straightforward mystery, not frenetic and full of red herrings and explosive action like contemporary thrillers tend to be. The big revelation is not hard to figure here, so those who are looking for a nailbiting finish may be disappointed, but this story moves beyond being a whodunit and a howdunit.

Social themes

But this is an Ambai novella, after all, and even while experimenting with a new genre, her interplay of important social themes does not go missing. With her sharp wit intact, she takes on police apathy, the epidemic of rape and various kinds violence against women, as well as the hollowness of family honour.

It's all the more brutal because you know this story is heavily rooted in reality, and such crimes take place every day, everywhere. This isn't the stuff of fanciful detective fiction, only written to shock or titillate. This is a haunting story, building up to a dark and impactful climax.

Although Ambai writes this new series with a lighter hand and keeps it more straightforward than her earlier work of fiction, her trademark feminist vigour lurks in these pages. She won't disappoint those who loved her stark, telling tales in Fish in a Dwindling Lake about the female body and gaze, journeys and tragedies; or her study of female fertility in A Deer in the Forest; or her exploration of gender roles and standing up against stereotypes and abuse in Unpublished Manuscript, or her deconstruction of restricted spaces for women in Kitchen in the Corner of the House, and indeed all her other important work written over four decades.

The theme in the new series centres on crimes against women in public and more importantly private spaces; her previous writing informs this novella in soft, subtle layers.

Here and now

In a sense, As the Day Darkens feels more contemporary, full of digital references, where Facebook and Google are diligently put to work as part of detective work. The lighthearted banter between Sudha Gupta and the cop on the case, Govind Shelke, her “rakhi brother”, is sharp and fun.

Her playful relationship with her 18-year-old daughter is reminiscent of the profound mother-daughter bond in Unpublished Manuscript. The soul of this novella is obviously the thoroughly endearing detective, and with this Sudha Gupta may well emerge as a detective worth turning to when you want a good old fashioned crime story, the story short enough to devour in one longish reading. Although her appearance is largely left to the reader's imagination, it seemed to me she was very real, perhaps a distinguished, dignified looking woman with streaks of grey, twinkling eyes, a warm smile, and a mind constantly ticking over – much like Ambai herself.

As The Day Darkens, Ambai, Juggernaut App.