LUDLOW filmgoers will have expert tuition as they prepare to dance the timewarp at a special late night showing of The Rocky Horror Picture Show.

The cult movie, with Tim Curry and Susan Sarandon, is being shown at the Assembly Rooms as part of the Silk Top Hat Gallery's series of classic films.

To help newcomers, or Rocky Horror virgins as they are known to insiders, a group of die-hard fans called Les Vulnerables will be on hand to explain some of the mysteries in a pre-show session.

Before the showing at 10pm on January 17, Les Vulnerables will take the audience through such vital points as how to talk back to the actors on screen and how to dance the timewarp.

Since it first appeared in 1975, the film has acquired a strange collection of extras and its very own etiquette - not to mention a few props. It is all very different from that other great audience participation movie The Sound of Music.

Dressing up is optional but that does not stop regulars turning up in high heels, a basque or perfect copies of costumes from the film.

The invaluable www.timewarp.org.uk (no hyphens, no spaces) website sets out four basic rules. Suits are worn only by people who thought they were booking for Phantom of the Opera or Chicago; don't wear anything that may be damaged by water, rice or occasional naked flames; avoid sandals or anoraks; and don't wear a sweatshirt with stripes.

There is a whole catalogue of props, including rice and confetti for the wedding scenes, a newspaper to wear over your head in the rain scene, toast to be thrown during the dinner scene and rubber gloves for the creation scene. Prop bags, containing all the essential equipment, will be available for £1 each.

For those who just want to sit and watch a great film in a more sedate environment, there will be a second showing on January 19 at 7.30pm. "Mad and Bad" cocktails will be on sale at the bar for both performances.