It’s fair to say The Rocky Horror Show is a well-oiled machine; even audience participation, honed over more than three decades, follows a tried-and-tested 'side script’ of perfectly-timed prompts, comebacks and choice epithets...

For all the frenzied fun and delirious plot, this minutely-orchestrated mayhem holds few surprises for superfans and dabblers alike (The Narrator said it best when, taking a rather foul-mouthed spectator to task last night, he mock scolded: “Don’t spoil it for the four people who haven’t seen the show before").

Or so we thought anyway, ready to ease back into the familiar quips and general naughtiness.

Then, Rocky took centre stage, flexed his biceps, launched into an Olympics-worthy routine of back flips, handstands and assorted acrobatics and nailed an L-sit before scooping Dr Frank’n’Furter into his taut guns as you would a bag of sugar.

Casting athlete Callum Evans was a stroke of genius – even bewigged Rocky Horror vets joined the chorus of oohs and aahs. A simple but surefire trick to zhuzh up the beloved musical.

Perhaps the two were unrelated, but it seems the new production's out-of-the-box tack inspired the aforementioned superfans to go off script for once, bleating just about anything that crossed their filthy minds to general hilarity. Going rogue, a vocal spectator two rows back took to barking utterly bonkers comebacks (prompting The Narrator to hail Bath as the “fifth smuttiest World Heritage Site in Britain” – high praise). In one riotous instance he beat Brad (Ben Adams) to his own line. A true sport, Adams stifled a giggle before gamely soldiering on.

Now for the plot (for the four of you, as estimated by whip-smart Narrator Steve Punt, who haven’t yet been swept up in Rocky Horror mania).

The mile-a-minute romp follows Brad and Janet, two freshly-engaged squeaky clean college kids. When their car breaks down throwing them into the path of Dr Frank’n’Furter, a mad inventor/cross-dresser intent on corrupting the virginal pair, they get sucked into a mind-blowing world of fish-nets, sexual fluidity, non-stop frolics, Frankenstein-style genetic tinkering, and sheer lunacy.

A perfect storm of camp and charisma, Stephen Webb doesn’t hold back as Frank’n’Furter. His rendition of Sweet Transvestite had the audience in raptures – deservedly so. Belting out the usual head-boppers with a deliriously devilish gusto, the energy of this ragtag cast breathes life into what has become the definition of a cult classic. A glorious ode to fun, excess and all-out silliness, it had us thrilled, chilled and fulfilled!

The Rocky Horror Show runs at the Theatre Royal bath until Saturday, May 11.

Marion Sauvebois