Did they all live happily ever after? That's up to you...

A new digital novel will overturn centuries of literary tradition by allowing readers to choose how they would like a story to end.

99 Reasons Why, a 99-chapter family drama about obsession, offers a choice of 11 possible endings. The conclusion depends on the reader's tastes and mood and on their answers to multiple-choice questions on colours, numbers and objects.

The idea came to its Newcastle-born author, Caroline Smailes, on hearing that some readers wished the dark stories in her two earlier books had had less gloomy dénouements.

For her latest work she decided to make every reader go away contented, with endings ranging from a "happily ever after" to a grisly Quentin Tarantino outcome. Star Wars and Brief Encounters versions are among others.

She told The Independent: "Different readers will have different reactions, interpretations and feelings about the story, depending on which ending they choose. This is the reader taking responsibility for the ending."

Her publisher, Scott Pack, said recent advances in ebook software had made such interaction possible.

"I'm not aware of anyone having done this digitally yet," he said. "There is more [technological] freedom now. So we wanted to exploit that."

As head of The Friday Project, a HarperCollins imprint, and of digital product development for the publisher, he is exploring experimental ideas for the digital age and sees enormous potential in such interactive books for adults and children.

99 Reasons Why, out next month at £7.99, tells of a housebound woman who spies through her bedroom window on the world outside while her family pursues lives of crime.

Smailes said: "The book was never intended to be in a print version, which is an unusual signing and which altered how I approached writing it."

Readers with a Kindle or other device answer simple questions according to their interpretations of the characters. The combination of answers determines the ending.

Readers can reread it for a different ending or even read all the endings by answering questions differently. Pack said the technology was more than just a gimmick. "These things tend to fail if they're just an after-thought," he said. "The whole book is structured, leading to these alternative endings."

Smailes got her initial break as an author through her blog. Her 2006 debut novel, In Search Of Adam, is a dark story about the impact of a mother's suicide on her child.

Ultimately, it is about the quality of the writing. Pack said: "Caroline can write about incredibly tragic and moving subjects but with such a lightness of touch. It's an easy read."

The only snag is for people who like to read the ending of a novel first.

Classics retold: Alternative endings

Liam O'Brien re-imagines the conclusions of literary favourites:

The Great Gatsby

Tom Buchanan admitted his part in Gatsby's death. Moreover, he realised that in their lives of endless folly, in their trendy East Egg triumphalism, he and Daisy had always been beautiful little fools. Satisfied, Nick beat on, boats with the current, borne forward ceaselessly into the future.

Wuthering Heights

Yes, Heathcliff thought. I have been a bit of a nuisance, what with locking Cathy in a room for five days and forcing her into a loveless marriage. On this sudden and unpredictable realisation, the ghost of Catherine Earnshaw inexplicably appeared before him, saying they would be together in the afterlife.

1984

The proletariat, suffused with an anger and vigour their former masters would have deemed doubleplusungood, razed the ministries of Peace, Plenty, Love and Truth to the ground. As icons of his disgraced leader were offered to the surrounding fires, Winston reflected. He hated Big Brother.

The Remains of the Day

Dispensing with the dignity, the stiff upper-lipped madness that had silenced his urges all his life, Stevens abandoned his service with Mr Farraday to indulge his passionate lust for the married Miss Kenton. "Sod my husband, and our future grandchild," she said, as she was spirited away.