Peter James: A great plot – with a twist

Ever suspected your house is haunted? For Hallowe'en, bestselling crime author Peter James recalls how he found ghoulish guests at his ancient Sussex home

My home is just outside Lewes, 15 miles east of Brighton. It's an area with literary connotations. It's where the Bloomsbury set lived, and we are 400 yards from the river Ouse, where Virginia Woolf drowned herself.

I previously lived in a Georgian manor house in Sussex. It was beautiful, but with old houses, you have problems; when it rained, there were leaks and I had to put buckets on the landing. So I wanted something more modern.

I bought this house at the end of 1998 when Helen and I moved in together. It had been a ruined barn, a granary and a farmhouse. The previous owner joined them all to make one house. It is part-conversion and part-new build. It's 8,000 square feet in all, with a nice feeling of space and light. What attracted me was the position. It's on the Downs, has 360-degree views and is half a mile down its own drive, so it's wonderfully isolated.

We have three reception rooms, seven bedrooms and four bathrooms. The previous owner did the place up beautifully with quality materials. All the wood is oak and we've a lot of oak flooring and bare brick inside. The walls are painted off-white. We've huge floor-to-ceiling windows in the open-plan living area, so we've used mostly natural colours. It's better to keep it simple when you've all that light. The kitchen is the one thing we would change. It has a full-size Aga, but it's small and shut away. We'd like a huge country-house kitchen.

Odd things started happening soon after we arrived. I moved into a study that had been used as an office. I was working on a book called Faith and couldn't focus on it. I felt very uncomfortable in the room. Quite often the front doorbell would ring in the middle of the night, and we'd smell cigar smoke. Helen's mother came to stay and was looking out at the garden when she asked, "Do you let your neighbours walk through the garden?" I said, "No." She said, "I've just seen nine people walk through the courtyard all dressed in medieval clothing." Then we had a party, and put out a clothes-rail on wheels for the coats in the library. A friend was sitting reading, and watched this rail trundle the length of the library.

We got a medium to come here and he went dowsing around the house with divining rods. He'd done some research and told us that there was a famous battle in Lewes in 1264 and the area around us was used as a burial ground for the victims. The battle was known as the Second Barons' War. Up until Henry III's reign, most cities were controlled by barons. Henry III was trying to bring everything under control of the monarch, and Lewes (under a baron called Simon de Montfort) was one of the last places to hold out. The medium said there was a grave under the desk in my office and that I was unable to concentrate because of a disturbed spirit.

We spent a whole day having the exorcism and the house settled down a lot. The light in some of the rooms changed perceptively. I moved my study to a room upstairs. My old study is now a spare bedroom but guests are not that comfy in there. We often find they sleep with the door open and the lights on. There are still strange happenings. I was away on a book tour one night and Helen felt somebody get into bed with her. She felt the bed moving and our two dogs who sleep in the bedroom were quite disturbed. I joke that it was Helen's secret lover.

Our house is a real mixture as I collect modern paintings but we also love antiques. Helen's family were furniture manufacturers in Sweden for generations and used to make furniture for the king's palaces. So we've some interesting pieces, including a huge, ornate drinks cabinet, a wonderful organ and a beautiful formal sofa and elegant armchairs.

We've a tennis court, a courtyard and an acre and a half of cultured garden. The rest is mostly wild fields. There are a lot of outbuildings – I'm a car nut and I keep modern and old cars in them. I race classic Citroën 2CVs. I have two. I recently sold my E-type Jags and an Aston Martin. In the grounds there is an old medieval hovel, which dates back to the Domesday Book. It has an ancient wooden roof and flint wall. Part of it is fallen down and now it's open-sided. We just use it to store barbecues and chairs and stuff. It's very peaceful there, and when I am in the primitive building, I think of the farmer who would have lived there 500 or 600 years ago with his livestock, which would have kept him warm in winter.

I would hate to move. We also have a flat in Notting Hill and some months I'm hardly in Sussex. Sometimes I think it might be sensible to have something smaller in the country. But at the moment this is my oasis, and I love the contrast with London. I love crossing the Downs and arriving to complete silence except for the bleating of the sheep and the sound of the wind.

Peter James is one of the UK's bestselling crime novelists. His Roy Grace detective novels, set in Brighton, have sold more than two million copies worldwide and been translated into 28 languages. His latest book, Not Dead Enough, comes out in paperback in December. He lives with his partner, Helen, in Notting Hill and on the South Downs, near Lewes, in Sussex.