Travel: Where death lurks among the cloisters

Britain's favourite television detective returns to the screen next Wednesday. Linda Cookson trawls Oxford in search of the real Inspector Morse

Next week sees the 32nd Inspector Morse film coming to our screens, and, if past performance is anything to go by, the surge of electricity accompanying the nation's dash for its kettles at half-time should signal an audience of some 13 million viewers. And that's just in the UK: 750 million crime fans world-wide are said to be riveted by the exploits of Colin Dexter's morose, real-ale-swilling detective. Eva Wagner, my guide on a special walking tour round "Inspector Morse's Oxford" was happy to bear this out.

"Especially the Belgians," she beamed. "You'd be amazed how many Belgians we get."

Now normally, with or without Belgians, I wouldn't be seen dead (sorry, Morse) on a walking tour - especially in a city where I lived for nearly 20 years. But you have to admit that there's something intriguing about the thought of a licensed snoop around a crime scene. And, after all, if Oxford Information Centre can run a CS Lewis tour and a Lewis Carroll tour, why not a Sergeant Lewis tour too, in honour of Morse's long-suffering sidekick?

So I joined my fellow Morse enthusiasts at the appointed hour in front of the Old School House in Gloucester Green. A brisk introduction put us swiftly through our paces. The first Morse novel, Last Bus to Woodstock, was published in 1975 ("the result of a rainy holiday in Wales"). However, it was the first TV adaptation in 1987 (of The Dead of Jericho) that really brought the characters into the public eye. Now John Thaw and Kevin Whately (playing Morse and Lewis respectively) are national heroes. Oxford's fictional body count is heading towards an impressive 80 corpses. And so on and so on.

Then things got a bit more shocking. Not all the Inspector Morse episodes are really filmed in Oxford, confessed Eva. Thames Valley police station is a Territorial Army building in Harrow, and Morse's flat is in Ealing. The plot thickens. Biggest shock of all: the famous maroon Jag doesn't run any more. ("Hasn't done for ages," said Eva airily. "It's carted around on a trailer.")

And then we were off. First stop was the city's Randolph Hotel, location of many a Morse incident but most notably where the American tourist, Laura Poindexter, meets her end in The Wolvercote Tongue. The Randolph is still deluged by eager Americans keen to book into Room 310 and repeat the experience.

The Wolvercote Tongue was a TV film from a Colin Dexter story line that the author later adapted into a separate novel, The Jewel That Was Ours; and the relationship between films and novels became a fascinating side- issue of the tour. The Morse of Dexter's novels began life driving a Lancia, for instance, but has now adopted the trademark Jag of his TV counterpart. Dexter's Lewis has transformed even more dramatically in recent novels - losing 20 years and a Welsh accent in the process.

Still on the theme of The Wolvercote Tongue, we were shown the Ashmolean Museum (intended showcase for the novel's missing treasure) over the road from the Randolph, before heading across St Giles to see St John's College.

This, as ardent fans will already know, is where Morse studied for his degree a decade or two before Tony Blair. ("Though Morse never finished his degree, of course," Eva reminded us. "Morse the pity," said a wag in our group.)

Then it was off to the Pitt Rivers Museum, where you can now buy postcards, signed by Colin Dexter, showing the Rhodesian hunting-knife that was stolen from cabinet 52 to become the murder weapon in The Daughters of Cain, and from there to the Sheldonian Theatre. In Twilight of the Gods, Wren's mini-masterpiece appears in all its glory when Sir John Gielgud (in full vice-chancellor's regalia) leads the University's Encaenia procession down Broad Street.

"Now, if you look up there," said Eva, pointing to a window in the facade of the Bodleian Library, "you'll see where the shot was fired that hit Gwladys Probet."

I was having the time of my life. We paused at the Holywell Music Rooms, where the aforementioned Welsh diva gave a masterclass before her encounter with the bullet, then skipped from college quad to college quad, merrily identifying where individual scenes were filmed. We visited Brasenose College, model for the fictional Lonsdale College. And Eva revealed treacherously that filming composites are routinely created if a college doesn't quite pass muster au naturel. In The Infernal Serpent, for example, Merton and University Colleges have been given the cinematic cut-and-paste treatment.

Even better, we then embarked on a flurry of pub-spotting - not difficult, this, since both books and films function very effectively as alternative pub guides.

We spotted the Turf Tavern, where a heartbroken Morse saw Ruth Rawlinson with another man in Service of All the Dead. One chap looked as though he was going to make a break for the bar. ("Later," said Eva, firmly, understandably keen to deliver us back to Gloucester Green within the allotted two hours.)

At the end of the tour, Eva gave us a quiz. Having already done some homework for this article, I was the class swot, and glowed with pride. What will be the new Morse on ITV at 8pm next Wednesday? The Wench is Dead, written by Colin Dexter and adapted for the screen by Malcolm Bradbury.

What will be different about it? Well, some of the action will be set in the last century, and there'll be rather less Oxford than usual: the Randolph, Bodleian, Oxford Gaol, Trinity College and Wadham College will all feature, but canal scenes have been shot elsewhere.

And what else will be different? Now here's the real bombshell. There'll be no Sergeant Lewis this time. Lewis signs up for the off-screen inspector's course and his place will be taken by a Keble College-educated newcomer, Detective Constable Kershaw (played by Matthew Finney).

One final question, before we headed off to revisit some of those pubs. What has Colin Dexter got in common with Alfred Hitchcock? Up shot my hand: they both make cameo appearances in their own films. So look out for Dexter in the opening shot of The Wench is Dead. He'll be studying an exhibition of Victorian crime. But be warned - blink and you'll miss him.

Inspector Morse appears on Wednesday on ITV at 8pm. Tours based on the films resume in March (until October) on Mondays, Wednesdays and Saturdays at 1.30pm. Adults pounds 4.50, children pounds 3. Tickets and information: Oxford Information Centre 01865 726871