WHEN the world’s highest-earning novelist launches his new thriller in January, his co-author may not be familiar to Western fans. James Patterson, an American crime writer whose estimated annual revenues of $95m dwarf even those of Harry Potter’s creator, J.K. Rowling, sometimes joins forces with local writers when he sends his investigators abroad. “Private Delhi” will be his second murder mystery with Ashwin Sanghi, a novelist from Mumbai who is far better known among Indian readers for his contribution to popular mythological fiction—one of the most remarkable, but overlooked, publishing stories of the past decade.

In the age of Patterson, Potter and “Game of Thrones”, Indian authors have brought their own special flavours to the table: mass-market fiction based on reinterpretations of the two great Hindu epic narratives, the Ramayana and the Mahabharata. Canny authors enlist ancient fables of gods and heroes, of rival clans, gigantic battles, perilous quests and fearsome ordeals as a way of unlocking the crowd-pleasing genres of mystery, fantasy and historical romance.

These stories have helped transform publishing in a nation of 1.3bn people with improving literacy rates and—in contrast to long-term trends in the West—a growing appetite for the printed as well as the electronic book. Adult literacy rose from 65% to 74% between 2001 and 2011; the projection for 2020 is 90%. The annual value of the book market has swollen to an estimated $3.9bn, with 90,000 new titles added each year. Chiki Sarkar (who is married to a correspondent in our Delhi office) used to run Penguin Random House in India and has now founded her own company, Juggernaut Books. She believes that the establishment of book chains that emphasise promotions has meant big books are becoming bigger, just as they have in the West. “Into this landscape you’ve now got an old genre that has found new vitality,” she adds.

The Ramayana and Mahabharata have long nourished Indian popular culture, whether through village storytelling, puppet-shows, television serials or Bollywood movies. Indian novelists writing in English used to be known abroad purely as a source of strenuous literary works; now they regularly produce gaudy blockbusters that marry these ancient tales with the latest trends in genre fiction.

The man credited with inaugurating this mythological revival is Ashok Banker, once better known as a literary novelist but who turned to mythological stories in 2003 with an eight-volume Ramayana series that began with “Prince of Ayodhya”. Mr Banker is now writing a screenplay for Disney India, a two-part adaptation of a subsequent series, drawn from the Mahabharata. “Frankly, what is happening now is not something new. It is simply a continuation of an age-old tradition,” Mr Sanghi says. “What makes it new is the language of choice—English.”

Mr Sanghi believes that the main reason why India lacked home-grown English-language bestsellers for so long was the condescending attitude of Indian publishers. Only after the spectacular success of young writers such as Chetan Bhagat, whose 2004 novel, “Five Point Someone: What Not to Do at IIT”, marked a turning-point, did things change. Dynamic Indian-based imprints began to exploit the newly discovered hunger for indigenous page-turners. The arrival of publishing multinationals, such as Random House and Hachette—which, from 2000, have been able to set up without an Indian partner—quickened the pace.

Some observers link the chart-topping mythology to the new assertiveness about Indian tradition that characterises the so-called “Hindutva” politics associated with the ruling BJP party and its leader, Narendra Modi, the prime minister. Christoph Senft, a specialist in modern Indian literature who teaches at Pune University in Maharashtra state, argues that a “search for internal homogeneity” has become the flipside of India’s rapid push towards the global marketplace. “Mythological texts confirm the Hindu nationalists’ wish to tell India’s history as a history of Hinduism.”

Some writers, however, mine the epics for stories and themes that have little to do with narrow chauvinism. Devdutt Pattanaik’s “The Pregnant King” hunts down gender-fluid elements in the Mahabharata cycle. Chitra Banerjee Divakaruni’s novel, “The Palace of Illusions”, tells that epic’s core plot of dynastic conflict from the feminist perspective of the resilient, much-married heroine, Draupadi. Mr Banker, the godfather of the mythological-literature boom, has always scorned the politics of caste or creed, and voices pride in his mixed, part-Christian background. Amish Tripathi, author of the “Shiva Trilogy” of racy potboilers, calls himself a “religious liberal” and uses only his first name on book jackets to avoid the upper-caste connotations of his surname.

The vast bulk of readers turn to these pages packed with divinities and demons for excitement and distraction rather than religious instruction. As Mr Sanghi says: “I have always maintained that my primary goal is to entertain, not educate or enlighten. If the latter two objectives happen along the way, that’s a bonus.”

Paradoxically, this reclaiming of traditional lore has also helped bring Indian publishing into line with international norms. For all their deep roots in native soil, myth-fuelled bestsellers fit snugly into a global entertainment market that is often driven by story-cycles such as “Lord of the Rings” or “Game of Thrones”. Ms Sarkar notes that the Indian bestseller list now looks more and more like mass-market fiction lists in Britain and America.

In common with several of his peers, Mr Sanghi started out in business before switching to writing novels with titles like “The Krishna Key”. He holds an MBA from Yale, and initially joined his family firm in Mumbai. Mr Tripathi, whose reported million-dollar deal for South Asian rights to a series of Ramayana novels made global headlines in 2013, worked in banking and insurance before he became a writer. Mr Pattanaik qualified as a physician. One of the most successful women authors in a now-crowded field, Krishna Udayasankar, whose “Aryavarta Chronicles” refashion the Mahabharata, still lectures in management in Singapore.

Why should India’s young professional dynamos turn with such relish to the distant storytelling past? Mr Sanghi argues that this group grasps the tools of “effective communication” but “does not carry the burden of a literary legacy”. Unlike literary-fiction writers, they feel “free to experiment”. Moreover, they know how to sell and are not afraid to involve themselves in marketing and distribution. Mr Tripathi’s “Shiva Trilogy” was initially published as a digital download by his literary agent after it received more than 20 rejections from publishers. He has promoted his books on a variety of platforms, including YouTube and even at cricket matches of the Indian Premier League; since 2010 “Shiva” has sold more than 2.5m copies. Each Indian generation folds myth into modernity. As Ms Sarkar observes: “The epics have always been in fashion.”