Stepping out on the Norwich Theatre Royal stage in An Inspector Calls

Waiting in the theatre's wings for our cue to go on stage was both a thrilling and slightly nerve-wracking experience.

As one of the local supernumeraries - or extras - in the play An Inspector Calls at Norwich Theatre Royal, I was lucky enough to be treated to a unique view of the detective thriller.

We were given the chance to witness the inner workings of the professional show behind the scenes while also watching the action unravel in the impressive stage set on which the Birling family house precariously balanced.

And as the story of what happens to the Birlings when a mysterious Inspector Goole arrives at their door unfolded, our big moment on the stage in front of an audience of 1,300 faces drew nearer.

The play by J B Priestley - seen by many as a critique of the hypocrisies of Victorian and Edwardian society and an expression of Priestley's socialist political principles - is a well-known classic that was first performed at the end of the Second World War.

However the role of the supernumeraries was added much later by director Stephen Daldry.

While the original characters played by professional actors are from 1912, the supernumeraries are from the 1940s and have lived through the two world wars which Mr Birling says will never happen in the show. Their role is to look on in judgement as the Birling family's secrets are revealed.

Charlotte Peters, the show's resident director, explained the characters were created after Mr Daldry noticed the inspector referred to 'we' rather than 'I' in some parts of the script.

'The supernumeraries come on as the moral conscience of the family, a group of people full of revenge who are there to support the inspector and they end up witnessing one of the most exciting and dramatic moments of the show,' she said.

Just hours before this dramatic climax in the show, I, along with about 10 other adult supernumeraries and three local children also joining the cast, had arrived at the stage door for the first time.

Some of us had acted in shows previously, others had never been on stage before, and everyone was excited about being part of a professional show.

Straight away we were whisked into the costume department to be kitted out in 1940s attire by wardrobe mistress Sarah Ford. I donned a pink floral dress, grey coat and black shoes before being sent to have my hair and make-up done by hair and make-up mistress Sinead Kennedy. As Sinead curled my hair and worked her magic with backcombing and hairspray the transformation was amazing, and when Sinead pinned the finishing touch - a grey hat - to my hair I can honestly say it felt like I had well and truly stepped back in time.

Next it was time to explore the set and find out more about how our characters were to cast judgement on the main characters. Without wanting to give too much away, the supernumeraries feature in two key moments which are packed with amazing special effects.

And while the supernumeraries stand together in a big group and do not speak, it was still rather nerve-wracking making sure you knew exactly where you were meant to be and what you were meant to do.

Strangely enough though, I was more nervous in the rehearsal than in the actual show itself.

For as our time came to step out onto the set's cobblestones in front of the packed auditorium, the magic of theatre took over. The nerves disappeared and I just enjoyed the moment - and the great privilege - of playing a small role in an amazing professional production.

All too soon it was over and the final curtain came down, but my night on stage at Norwich Theatre Royal is one I will remember for a long time to come.

An Inspector Calls - produced on tour by PW Productions Ltd run by Norwich Theatre Royal chief executive Peter Wilson - is at Norwich Theatre Royal until Saturday. To book, visit www.theatreroyalnorwich.co.uk or call 01603 630000.

Do you have a Norwich arts story? Email arts correspondent Emma Knights at emma.knights@archant.co.uk