Mohammed Hanif has always been a daydreamer. In his own words, he’s the type of guy that spends a big part of his time, ‘dreaming and scheming’. His daydreaming was one of the main reasons he joined the Pakistani Air Force Academy at the age of 16. ‘A lot of my friends wanted to be cricketers, or pop stars or astronauts. I dreamt about being a pilot. I really wanted to fly planes.’ But when all the other cadets were busy practising drill formations or polishing their bayonets, Hanif realised he was much happier hanging out in the library devouring the novels of Truman Capote and the South American magical realists.

So he left the Air Force and began a career in journalism. From then on his feet were forced to stay grounded in cold, hard facts, but his head still remained up in the clouds. ‘Journalists can be real pedants,’ says Hanif, who has written for the New York Times, India Today and Newsline before taking up his current post as head of the BBC’s Urdu Service in London. ‘They have to care so much about who said what, and when. I always dreamed about getting away from the day job to write fantasy and fiction where my characters could do whatever I told them.’

Now, as his first novel is published, he’s getting ready to quit journalism once and for all and go back to what he likes best: daydreaming. A Case of Exploding Mangoes combines his love of a good yarn with his background in political reporting, taking an imaginative look at what might have led to the mysterious death of Pakistan’s dictator, General Zia, in 1988. It’s an intelligent and playful read, where stories of real people and events are woven into Hanif’s visions like a neatly spun Persian rug.

There’s General Zia, the paranoid, housebound tyrant who flips open the Quran at a random page every morning, scrutinising each word like it was a personalised crystal ball reading. Or Officer Obaid, a silk-shirted, poetry-loving yoga fan, mincing his way around the military barracks. When he disappears, an official enquiry is launched and his friend, Officer Ali Shigri, finds himself imprisoned.

The storyline twists skilfully around religious fanaticism, torture, forbidden love and a blind woman waiting to be stoned to death for adultery, but what could be a heavy, uncomfortable read comes over as a warm, darkly witty thriller thanks to Hanif’s lightness of touch. ‘I never wanted to write an issue-based, provocative novel,’ he explains. ‘I’m just telling a story set in a particular period. It’s my duty to reflect what the mood in Pakistan was then. A lot of it is based on my memories, or rumours and jokes that were circulating at that time.’

Hanif was 22-years-old when Zia’s plane crashed, killing him and several of the country’s top brass, leaving behind a cloud of conspiracy theories. Growing up in Pakistan, the author witnessed the dramatic impact that Zia’s 11-year reign had on his country’s culture, steering it away from a time when army messes included their own bars, and religion was a personal and private pursuit, towards an oppressive régime where female judges could be fired for not covering their heads. When news reports came in that Zia had died, Hanif remembers people were stunned. ‘That lasted about 15 minutes; then everyone was dancing in the street.’

Two decades on, with Zia’s death still the subject of intense speculation, Hanif decided to try and solve the case through fiction. ‘I’ve always loved a good murder mystery,’ he laughs. Hanif began his research by tapping into his journalistic instincts, scouring history books for information about Pakistan’s notorious leader. He abandoned that approach pretty quickly though when all he found were pages of spin written by Zia’s sycophantic cronies. ‘They were describing this humble, god-fearing man,’ says Hanif of the individual who controversially introduced Sharia Law to Pakistan and ordered an extreme Islamisation of the country. ‘The stuff I was reading was all so banal; I needed to sex it up.’

A Case of Exploding Mangoes has already received praise from Pakistani authors including Mohsin Hamid and Kamila Shamsie, plus glowing reviews from British writers John Le Carré and Mark Haddon, but the book was turned down by several Pakistani publishers who considered it too risky. Hanif finds it ‘puzzling and worrying’ that his novel might be seen as a hot potato so long after Zia’s death, but hopes foreign audiences will enjoy reading fiction about a country often overshadowed in the media by its neighbours, Afghanistan and Iran.

Although A Case of Exploding Mangoes is Hanif’s debut novel, it’s not his first foray into fiction, having already written the script for The Long Night in 2002. The Urdu language feature film, about a naïve yuppie living in Karachi, went on to be shown at film festivals around the world. Hanif is keen to gradually bring more attention from the arts world towards his native Pakistan, where is moving back to later this year. He loves the idea of writing fiction for a living - a ‘far less stressful and demanding job’ than journalism - and has already ‘been scribbling away’ at a second novel.

When Hanif comes to the Book Festival in August, he is also bringing along his play, The Dictator’s Wife, which he describes as ‘a companion piece’ to the novel. Recently staged in Hampstead Theatre, Hanif is excited at the prospect of putting on a show at the Fringe. ‘I’ve been coming to Edinburgh for years now as a spectator,’ he says. ‘It’s exciting this time to go along with work of my own. I guess you could say I’ve been dreaming and scheming about it for years.’

Mohammed Hanif & Robin Yassin-Kassab, Charlotte Square Gardens, 0845 373 5888, 12 Aug, 7.30pm, £6 (£4)

Brian Donaldson unveils a clutch of debut authors also gracing the Festival

Poppy Adams

The Behaviour of Moths is a story of two elderly sisters reunited after almost half a century and unleashing a torrent of secrets.
9 Aug, 7.30pm, £6 (£4)

Yiyun Li

A Thousand Years of Good Prayers is a collection of short tales describing how myth, culture and history combine to shape a person’s fate.
11 Aug, 7pm, £9 (£7)

Jonny Glynn

The Seven Days of Peter Crumb focuses on an anti-hero with a week left on this earth and a determination to leave his mark.
15 Aug, 4.30pm, £6 (£4)

Ross Raisin

God’s Own Country features an adolescent who goes from oddball isolation in the Yorkshire countryside to all-out insanity as he stalks some ramblers.
15 Aug, 7.30pm, £6 (£4)

Sadie Jones

The Outcast tells of small-town hypocrisy in 1950s England as an unwanted homecoming sparks off community chaos.
22 Aug, 4.30pm, £6 (£4)

All events take place at Charlotte Square Gardens, 0845 373 5888.