Jericho Comedy has been consistently delivering weekly doses of stand up to adult audiences for several years, but their hugely popular wizarding parody is one of their first foray into children’s theatre, so I was intrigued as to how it would translate.

The Show That Must Not Be Named (“for legal reasons,” as it turns out, as “we don’t own the copyright”) is loosely based on the story of a certain young wizard at a certain Hogwarts Academy. But in this case, both the protagonist’s name and the setting of the villain’s lair have been plucked out of a hat at the start of the show from a selection provided by the audience. This early bit of interaction helped create a nice connection between actors and audience as well as keeping the troupe on their toes. We even got to vote on the name of the story itself from a choice of two, presumably rendering half the rehearsals redundant, but again adding another pleasing whiff of creative tension to the proceedings.

Thus it was that Tomes Spookhead embarked on his journey to the Great Greek Grondee in The Tale of the Cursed Beard. Without wanting to give too much away, Tomes is cursed by an unnatural outpouring of facial hair for his tender years, which is both the cause of much suffering and bullying, but also - unbeknownst to him - much coveted by the follically challenged Voldemort. After capture through the toilet pipes by Voldemort’s serpent servant, Tomes, seeing an opportunity to end his misery, is on the verge of surrendering his luscious chinlocks to the evil sorcerer, before being…well, let’s have no more spoilers shall we?

The key elements of the plot have clearly been sketched out in advance, and the beginnings and endings of each scene are tightly rendered. This leaves, however, much room for improvisation in between and all the players are clearly highly skilled in this department. My own children are most definitely not Harry Potter fans, and yet were won over very quickly by the comic performances and clever wit, pitched at just the right level for kids and adults alike. Some killer lines and some great impressions (a wonderfully uptight portrayal of Alan Rickman totally salvaged an otherwise pointless Severus Snape cameo) made this a consistently enjoyable performance. As with any improv, watching the actors putting each other on the spot, and successfully deliver in what, to us ordinary mortals, appear as pretty nerve-wracking circumstances, was a real treat.

It’s an ambitious format, pulled off with aplomb. The actors are definitely good enough to risk soliciting further directions from the audience, and it would be great to see future iterations of the show pulling additional characters, special powers, etc out of the hat throughout the performance and not just at the beginning. Although that’s easy for me to say, of course. We will definitely be there to see how it goes either way!

My husband and I are fully signed up Harry Potter geeks so were intrigued to see Friday's performance in Blackwell's: The Show That Must Not Be Named. I must state upfront – as did our host, Harry Househam, that the show is not at all, in any way, affiliated with J. K. Rowling, or Warner Bros or the actual Harry Potter. It is an improvised parody performed by an energetic troupe of five young actors who take ideas that have been written down by audience members and added to the Goblet of Fire to aid the creation of a new 'Harry Potter and the...' type story, depending upon the idea.

I was pleased to see the bookshop filling up nicely as we made our way to the 'bar' (fabulous - £2 wine – thank you very much Blackwell's Bookshop in the Westgate!) and there was a pleasant atmosphere humming through the mix of families, friends, students and couples attending. I'm always nervous that the sometimes-reserved British audience won't be responsive to this sort of show – joining in and throwing out suggestions – but I had nothing to worry about on Friday. We were given a brief five-minute warning and then the troupe bounded out onto the 'stage' (we were in a bookshop, don't forget). With a backdrop of floor-to-ceiling bookshelves scattered in Potter-posters and a trio of huge Potter-esque trunks (suitcases, not swimming shorts, that would be weird even for improv) I found it easy to ignore the real world for an hour or so and lose myself in the madness of Tight Five's imagination.

Houseman's hosting was brilliant - energised, fun and funny. We were thrown straight into a bit of an improv 'exercise' for his four Hogwarts students, where they had to carry on telling the story, without too much hesitation, while incorporating whatever ridiculous scenario or item was thrown into the mix from the Goblet. Or without using the letter S, for example. The audience joined in the joyous killing ('Avada kedavra!') of each student as they failed to meet the requirements of this exercise. Think Just a Minute, but in cloaks and with wands. And magical death. The kids in the audience were loving it. I include myself in that category for this particular show.

The main part of the show began with an awkward 'who in the audience gave us this idea' moment, which is what gave us the title of our performance 'Hannah Why and the Hipster Coffee Shop'. Hannah was happy to admit to the hipster coffee shop idea (and why not, it's a mine of fun-poking joy!) but when asked for her surname only answered with 'Why?!'. So our troupe just went with it and came up with a mad, rambling but clever and hilarious tale which began with a house-elf and a half-troll called Tomothy drinking fancy deconstructed coffee while not declaring their love for each other. We were then treated to a tri-wizard tournament presented by Barty Crouch Sr (a snooty Dom O'Keeffe) with a sylph-like Beauxbaton student, (played with all the stereotype stops pulled out by the hilarious Ed Scrivens) a meat-head Durmstrang student called Oliver Lightly Soiled Snow (an impish Francesca Forristal) and the very hipster Hannah Why played very cleverly by Vicky Hawley, especially amidst confusion surrounding whether it was her daughter (Hannah Jr, of course) who was entered into the tournament, or herself (she managed to play both roles). And every role in between filled by whoever wasn't on stage at that moment.

I laughed my flip-flops off and went straight home to watch a proper Harry Potter film. It was good, definitely more coherent, but nowhere near as funny as The Show That Must Not Be Named. I look forward to seeing more from Tight Five and Comedy in Oxford soon.