Yes, of course she has a Christian name — a very attractive one actually – but MG Harris, whose second children’s book has just been published, prefers to be known as MG, so that’s what everyone calls her.

If MG had not broken her leg and been confined to her house in Summertown for ten weeks in 2005, perhaps her successful writing career would never have got going.

Until that moment MG had been a scientist, working in various Oxford University laboratories on cell biology.

She and her husband Mark Salisbury also co-founded The Oxford Knowledge Company in 1997, which is the largest IT support company in Oxford.

She had always had it in the back of her mind that she would like to write a book, but as a mother of two whose work demanded a great deal from her, she had never had time to sit down and get on with it before the accident.

“The year before, I had been off work for a year. During that time I had come up with a plot and thought then that if I could write a plot, then I could write a novel, and if I could write a novel I could publish a novel.” And this is exactly what she did.

She was the fastest-selling UK debut children’s author of 2008 and has embarked on a series of five books for children aged nine to 19, which is an ambitious project by anyone’s standards.

MG’s first book, The Joshua Files: Invisible City, introduces the readers to Josh, a British teenager who goes to school at St Gregory the Great in East Oxford and whose archaeologist father is killed in a plane crash.

But is his father really dead? Were there UFOs flying overhead when he died?

Josh’s adventures really begin when he reads his father’s emails, which catapult him into Mexico in search of the lost book of the Mayan civilisation, the IX Codex. It is a fast-paced story of loss, loyalty and personal responsibility which is set firmly in the 21st century.

The second installment of The Joshua Files, called Ice Shock, continues the saga. At the conclusion of book one Josh had thought the worst was over – but it hasn’t even started.

This time, he finds he must journey to the secret Mexican City of EK Naab, where the riddle of the mysterious Bracelet of Itzamna awaits him. It’s an intriguing science fiction that takes the readers from Oxford to the jungles of Mexico and on towards the possible end of civilisation.

The author said: “I was inspired to make Josh the central character having met a young archaeology protege.

“I thought: ‘If a real boy can do this stuff, then my character can too’.”

She tried out her story on her 16-year-old daughter Josie, who was 13 at the time. When it became clear that Josie and her friends were enjoying it, MG gained enough confidence to go on and is now on her fourth of the five books.

“Once I have drafted out the plot, I find I can write quickly, and set myself the target of 5,000 words a week.

“ I really love writing, but admit to missing interaction with people at times. Writing is a lonely occupation. Apart from talking to my editor and agent, I hardly every have meaningful conversations these days. Working in Oxford as I did, I was once surrounded by brilliant people who were at the top of their field.”

However, plotting for not one, but a series of books, keeps MG’s active mind more than occupied, because as she explained, you can’t leave too much to happen at the end, in the last book. You have to add things as you go along.

She has identified Josh’s school as St Gregory the Great, because she is a Foundation Governor there and remained on the school’s Governing Body since the school opened in 2003.

She says the school, and the children who attend it, are delighted to be included and wait with bated breath for the day a film of the Joshua series is announced.

“Films take a long time to come to anything. It’s an ongoing conversation, and all in the future. First I have to get book four and five finished,” she said.

l Ice Shock (sequel to The Joshua Files: Invisible City) is published by Scholastic Children’s Books in paperback at £6.99.