In particular mystery authors, who over the last decade have proved to be immensely popular fodder for television series.

There is no denying that many people would never have experienced the idiosyncratic charms of Inspector Morse if the BBC had not filmed Colin Dexter's books over a number of years.

Indeed, most people - apart from mystery fans - would have not even heard of the inspector without the telemovies, and this is a similar case with many television detectives.

The challenge for librarians is to be on the hunt for new telemovies featuring detectives sourced from novels and then to make sure that we know who the author is and that we have a reasonable number of their titles on the shelf to prepare for the coming deluge.

It is a fairly safe assumption that all the books by a mystery author will vanish from the shelves within a few days of the start of a new series - books that may have been languishing on the shelves for many years are all of a sudden in demand.

The reason? The books are usually much better than the series of course - the reader can experience the thought processes of the characters, gather clues and evidence at the pace the author dictates - not at the pace of a 90 minute telemovie.

The reader also meets the main characters and is given their appearance, past history and nature in a way that cannot be imparted on the small screen.

Over the years, there have been a number of very unusual interpretations of series characters - imagine the horror of MC Beaton when she first saw Robert Carlyle playing her Scottish policeman Hamish Macbeth.

Beaton's character in the book is tall, thin and with bright red hair - it is a wee bit different to the screen character.

Similarly, the latest round of TV movies featuring the books of Elizabeth George have a dark stocky actor playing Inspector Lynley, who is described as tall, lithe, blond, aristocratic, etc... for the longtime reader of the author's mysteries, it can be a rude shock to see a character imagined in your mind, suddenly appear as nothing like you'd anticipated.

However, a series adaptation of an author's books can also bring huge rewards for both writer and publisher, so maybe it's not all bad news.

How many people can remember the Frost series with actor David Jason?

Hardly anyone knew the author's name (RD Wingfield), before the series, and the same applies to the Dalziel and Pascoe series (Reginald Hill) and many more.

Luckily, the library has an excellent range of mysteries of all the TV detectives you can think of, and a few you've probably forgotten. So if you are a bit of an armchair detective on Friday nights, why not try the original product - the book on which the movie is based.

And if you've forgotten some of the more popular detectives let me remind you - Inspector Wexford mysteries (Ruth Rendell), Hetty Wainthrop investigates (David Cook), Commander Adam Dalgliesh mysteries (PD James), the Wycliffe mysteries (WJ Burley), the Midsommer mysteries (Caroline Graham), Cadfael mysteries (Ellis Peters), and Inspector Rebus (Ian Rankin).

Happy detecting.

Note:Booklists on TV detectives and more are available in hard copy at the Library. They are also available from our web site. Please click here.