Sadhus in Allahabad, India charge into the waters of the Triveni Sangam (the confluence of the rivers Ganges, Yamuna and the mythical Saraswati) for a ritual bath

Nine Lives: In Search of the Sacred in Modern India
By William Dalrymple
Bloomsbury £20, 304 pages
FT Bookshop price: £16

William Dalrymple is now well established as India’s literary “Orientalist”, interpreting its historical intricacies for a generation of international readers. His books, particularly his first on India, City of Djinns, are now prescribed reading for almost any visitor, and a favourite among street-hawkers at New Delhi’s traffic lights.

The Scottish writer’s latest book Nine Lives; In Search of the Sacred in Modern in India is one of his most ambitious yet, taking the reader into lurid, scarcely imaginable worlds of mysticism.

It is a neat study of the panoply of arcane religious devotion across south Asia. In his search, he uncovers a kaleidoscope of Hindu, Muslim and Buddhist traditions and is drawn to their outer fringes. He encounters animal sacrifice, epic poetry, trance and a fearsome realm of spirits.

At their most tawdry, his travels reveal blighted lives of sexual slavery and mean caste divisions; at their most heroic, he finds great warrior kings and acts of barely comprehensible self-sacrifice.

The nine lives of the title are touching, otherworldly personal vignettes. The subjects are carefully chosen. Among them are a Jain nun who wipes the steps in front of her with a peacock feather to avoid killing insects, a Tibetan monk who has renounced non-violence to take up armed struggle against China and a Sufi “holy fool” facing the menacing tide of a stricter Islam in Pakistan.

Dalrymple has an inimitable way of conjuring the Indian landscape – whether desiccated or fertile – and its colourful religious practices. With the eye of someone who has lived on and off in Delhi for nearly two decades, one of his greatest charms is his observation of India’s combination of the sacred and the mundane.

In one of the studies, Hari Das, who for most of the year is a manual labourer digging wells and a prison warder, has a seasonal job as the god Vishnu in Keralite religious performance – akin to the morality plays of medieval England. Das dresses as the god for energetic night performances in which he is possessed by the god’s spirit. In the climactic scenes, Vishnu drinks the blood from the freshly severed neck of a live chicken.

In his divine role, the labourer is revered by upper castes that under normal circumstances would not deign to have him cross the threshold of their houses. When not being Vishnu, one of the most powerful gods, he is thoroughly down to earth, casually talking to Dalrymple as he emerges from the shaft of a well, or as he cleans greasepaint from his face after a show.

Behind the devotion and sense of the epic is always a strong sense of human frailty. Descriptions of exotic, transcendental ritual are intertwined with painful personal narratives. An overwhelming sense of fragility surrounds India’s sacred worlds. In almost all of the tales is a sense of personal tragedy or the ending of an era. Many of the sacred roles are handed down from parent to child, and those ties are loosening.

A bronze idol maker in the south faces the prospect being the last of his line as his son is more interested in being a computer programmer in Bangalore than keeping up the family tradition of Chola bronzes. An oral poet in Rajasthan dies of undiagnosed leukaemia without finding a hospital bed for his last, painful days. A woman devoted to a goddess in her childhood is given over to prostitution and becomes infected with HIV/Aids.

Dalrymple, as always, impresses with his scholarliness. He explains the religious context of his subjects with erudition. Just as he brought to life Mughal emperors in his earlier work, he delights here in his descriptions of Sufi fakirs, Shaivite sadhus and sadhana, or Tantric rites.

Yet it is always the human story that triumphs. Nowhere is this more so than in the chapter on “The Red Fairy”. She is a passionate devotee of Lal Shahbaz Qalander, a Sufi saint in the Pakistani province of Sindh. She is also a peculiar, almost freakish sight: “ ‘Her name, he said, was Lal Peri Mastani, or the Ecstatic Red Fairy. I asked how I would find her amid the crowds.

“ ‘Don’t worry,’ said the fakir. ‘Everybody knows Lal Peri and anyway she is unmistakeable.’ In what way I asked?

“ ‘She is dressed in bright red, is very fat, and she carries a large wooden club.’ ’’

Lal Peri’s own life is as striking as the current tensions between Pakistani Sufism and gathering influences of a stricter form of Islam from the Gulf. She is a Muslim refugee from Bihar, one of the poorest states in India, who first moved to Bangladesh before then moving to Punjab in the east – each time fleeing from communal killings. Her final refuge, the shrine, is itself now threatened by the advance of the Taliban.

Just as Lal Peri wields a wooden club, Dalrymple’s most powerful weapon is his ability to shock. One of the most austere chapters is also the most disturbing. “The Nun’s Tale” describes a Jain nun who on the loss of her sisterly companion starts out on a road of steady deprivation – or sallekhana – by gradually withdrawing elements of her diet until nothing is left. Extraordinary self-control holds the key to self-destruction too.

Chapter headings, such as “The Monk’s Tale” and “The Nun’s Tale”, invite comparisons with Geoffrey Chaucer’s The Canterbury Tales. Identifying a common thread in Nine Lives, however, is elusive. Moral lessons are dwarfed, as so often in India, by the simple matter of survival. Modernity still barely intrudes on fraying ancient ways.

The Chaucerian journey from London to Canterbury revealed the emergence of a modern, commercial class. Times were changing, as were attitudes and values. Times are changing, too, in India. A fast-growing economy is sweeping some of the old attachments aside. Dalrymple’s journey, from the high-rise office towers of Gurgaon to the fortress walls of Jaipur, reveals a pilgrim people straining for spiritual substance. Much is sacred, only a little is modern.

Future journeys may show India the other way around.

James Lamont is the FT’s south Asia bureau chief