THE doctor's orders were to stay in bed and Prof Susan Parry reluctantly listened.

She'd been suffering from a mysterious virus for a week and was thoroughly fed up, not being the type to take to her bed at the hint of an illness.

"I was feeling really, really rough," she said. "I was in bed, but got up to go to the bathroom - and my legs just collapsed.

"Within 24 hours, all feeling had gone from the neck down."

Prof Parry, a professor of analytical chemistry at Imperial College London, had been on a high. Her first novel, Corpse Way, had been published a few weeks before.

Now she found herself lying on the floor of her Surrey home, unable to get up.

She eventually managed to drag herself back into bed. "I was strangely calm," she said. "I thought My husband will be home in a few hours, I will ask him what is wrong', and I just lay there, waiting for him to come back."

Prof Parry was immediately admitted to hospital by a sharp-eyed doctor, who suspected what was wrong and wrote on her notes: "Possible Guillain Barre Syndrome".

She was diagnosed with the auto-immune disease, which she described as being like MS, but reversible, and spent six months in hospital. The first seven weeks were spent in intensive care on a ventilator as her lungs were affected.

Slowly, after being given doses of immunoglobulin, she began to regain some movement in her arms.

"It was a long haul then," she said.

"I had to learn to walk again. I had no strength at all as my muscles had completely gone and I was in a rehab unit in a little cottage hospital for six months."

The slow process of learning to walk, brush her teeth, even use a knife and fork again, had begun.

When she was able to move into a wheelchair, the intensive physiotherapy started.

She said: "It was just like in a Hollywood film. They hauled me up to these bars and I had to walk along them. They would ask me to climb two steps, and I would only manage one, and they said that was great.

"But I was so confused because I felt I'd failed and I should have been able to climb two."

Prof Parry wasn't able to work on her novels while she was ill. "I couldn't even hold a book and listening to music was difficult. For a long time I wasn't able to do very much. I became totally institutionalised,"

she said.

"I even had to learn how to use a knife and fork again, like a baby, because the grip wasn't there. It was a problem in the connection between the brain and the limbs."

It was another year before Prof Parry was able to visit her beloved second home, a farmhouse in Swaledale, as she was unable to climb stairs or walk on uneven ground.

When she left the rehab unit in March 2006, she could walk with two sticks and her recovery since then has been remarkable, helped by one-to-one Pilates classes, which built up her strength.

The only evidence of the disease is a small lack of feeling in her toes and she is now able to walk seven or eight miles in the Yorkshire Dales again.

She said: "At first, balance was a problem and it was hard to walk in uneven fields.

"It feels like very hard work, but that's because your brain is having to work so hard."

Prof Parry has just published her second novel, Death Cart, which, like her first, is based in the Dales.

Death Cart follows Millie, a student archaeologist working on a chariot burial in Wensleydale, who finds herself caught up in a modern- day mystery.

Prof Parry said: "I have always been very interested in crime novels.

It is like compiling a crossword.

All the different parts have to tie in and you have to develop elements of surprise.

"My favourite writers are P D James and Ruth Rendell, but when I'm writing I try not to read crime novels in case I subconsciously pick up the plots."

She writes very scientifically, with a spreadsheet monitoring her aim of writing 500 words a day and another spreadsheet showing timelines and what her characters are doing at different points in the novel.

Her novels also draw on some of the real-life cases she has worked on.

Prof Parry is an expert in the field of forensics and environmental science and has done a lot of consultancy work with her colleague, Prof Kim Jarvis.

She worked on the high-profile Chohan case several years ago and her evidence about matching soil samples helped to convict gangland boss Kenneth Regan and his two accomplices for the brutal murders of the entire Chohan family, including an eight-weekold baby.

Her techniques have also helped authenticate the date of paintings by analysing paint samples, including a work ascribed to Leonardo Da Vinci, entitled the Holy Infants.

Prof Parry's farmhouse in Swaledale is perched on the side of a hill above Low Row, with sheep grazing in a neighbouring paddock. She spends as much time there as her busy schedule allows and has plans to retire to Swaledale.

Her books have been published through her own publishing company, Viridian, which also publishes her academic texts.

She said: "We set up the company to publish an academic text in paperback and were surprised how straightforward the process was. I then admitted to my colleague that I had written a novel and she said we should publish it.

"The local shops were very supportive of the first book and Ottakars had it on a stand as I was a local author, but unfortunately, now they are Waterstones, they are no longer able to do that.

"It would be nice if my books encouraged people to visit the Yorkshire Dales.

"Swaledale is beautiful, probably one of the most unspoiled parts of England."

Death Cart and Corpse Way are available in the Castle Hill bookshop in Richmond, and in some Dales newsagents. Copies can also be ordered from Viridian Publishing by visiting www.viridianpublishing.

co.uk.

Prof Parry's third novel is based in Ingleton and the Skipton area and is still a work in progress.