Date: 9th August 2026
Time: 9.20pm
Venue: Underbelly Bristo Square, Dairy Room
Running time: 60 minutes
Rating: ★★★★★
Reviewed by: Kaitlyn Smith
Under the Influence might just be my favourite show of the Fringe so far, which I really wasn’t expecting when I walked in.
Created by identical twins Carine and Frances Gilbert alongside Shona Maule, Under the Influence is an original musical comedy set largely inside a therapist’s office, where Carine and Frances have ended up in therapy together. Yes, together. Because apparently even therapy is something they have to share.
The pair are best known online as The Gilbert Twins, where they have built an audience of more than three million followers, and slightly embarrassingly, it took me until after I’d already decided to book the show to properly clock that I knew exactly who they were. I’d actually followed them from pretty much the beginning without even realising it, with their dancing videos and light-hearted comedy regularly appearing on my For You Page. That was the version of The Gilbert Twins I knew, so the musical theatre side of them was completely unexpected, and I hadn’t connected Under the Influence with the two people I’d already been watching online for years.
The show takes that very public version of their relationship and looks at what happens behind it. They live together, work together, share friends, share a career and have spent their lives being known as a pair, but underneath all of that they don’t necessarily want the same things anymore.
That sounds considerably more serious than the first part of the show actually feels, because it is very, very funny. The therapy setting gives them plenty to play with, particularly when their therapist Kate starts trying to work out whether their life online might have something to do with why they’re sitting in her office in the first place. Social media, influencing, relationships, ADHD and the general chaos of being so intertwined with another person all get thrown into the mix, often through songs which are ridiculously catchy.
I loved the music almost immediately, and this was probably the biggest surprise for me because I had absolutely no idea either of them came from musical theatre. Carine and Frances are both trained musical-theatre performers, which suddenly made a lot of sense once I heard them sing because their voices are incredible. Some of my favourite musical moments came when they were singing together because their harmonies are gorgeous, but the strength isn’t just in their vocals. The songs are incredibly well written, properly catchy and actually earn their place within the story, whether they’re being used for comedy, pushing an argument forward or allowing the pair to say something they haven’t quite managed to say to each other yet.
There is also something quite brilliant about watching two identical twins sing about desperately wanting to be seen as individuals while simultaneously sounding so perfectly matched together.
At the centre of it is a fairly straightforward problem. Carine wants to start building more of a life of her own, while Frances is struggling with what that could mean for the life they’ve always had together. One has a boyfriend, there is talk of moving out and suddenly the things which have always made their relationship work begin to feel slightly different when one person starts imagining a future that doesn’t automatically include the other in every part of it.
It would have been very easy to make one of them the unreasonable one here, but Under the Influence doesn’t do that. You can understand why Carine wants independence and the opportunity to find out who she is outside of being one half of The Gilbert Twins, while also understanding why Frances finds the prospect of their lives changing so difficult. When you’ve shared almost everything with another person for your entire life, where exactly does being a twin end and being your own person begin?
And then the show changes.
I don’t want to explain exactly what happens because I went into Under the Influence knowing very little about where the story was going, and I think that’s the best way to see it. What initially looks like one twin being resistant to change becomes considerably more complicated, and there was a point towards the end where my entire understanding of what had been happening between them shifted.
Frances has a solo during this section which was probably my favourite musical moment of the entire show. I don’t know the name of the song, so I’m not going to pretend I do, but it is beautifully written and gives her the space to finally put into words how she feels about her sister and the possibility that, despite loving her so much, she might also be standing in the way of Carine becoming her own person.
And yes, I actually shed a tear.
Considering we’d spent so much of the previous hour laughing, I wasn’t expecting Under the Influence to get me like that at all, but it did. The emotion doesn’t suddenly appear because the show has decided it needs a serious moment before the ending either. Once everything starts coming together, you realise that a lot of what seemed funny earlier was also quietly setting up something much bigger about their relationship.
Knowing that there is some truth sitting underneath the story makes it hit even harder. Carine and Frances have said that the musical was inspired by a difficult period in their own lives which they hadn’t previously shared online, although what we’re watching is a heightened version of events rather than everything happening exactly as we see it on stage. For two people whose careers have involved sharing so much of themselves with millions of people, there is something quite lovely about them using theatre to tell a story about the parts of their relationship that haven’t been shared with those millions of followers.
It also never loses the relationship between the two of them underneath the bigger themes. Yes, it’s about influencing and the pressure of living online, and there are questions about identity, independence and what happens when your career is tied to another person, but more than anything it felt like a show about sisters who absolutely adore each other while also occasionally wanting to strangle each other. Which, frankly, feels pretty believable.
The fact that they are actually twins adds something that would be incredibly difficult to manufacture with two unrelated performers. Their timing is brilliant, their chemistry is completely natural and when they sing together their voices blend beautifully, but it is the emotional side of their relationship that ultimately makes the show work. You believe the frustration because you believe the love underneath it.
There are also some brilliantly ridiculous moments along the way, and the show knows exactly when to break its own tension. At one point Kate attempts to regain control of the situation, only to be met with the wonderfully self-aware response: “It’s a musical, Kate!” It sums up the tone pretty perfectly. Even when everything is beginning to fall apart, Under the Influence still knows how to make you laugh.
Under the Influence is funny, ridiculous, incredibly catchy and then, somehow, properly moving as well. Carine and Frances are fantastic performers individually, but watching them together is what makes the show special, particularly when the comedy starts dropping away and you see the relationship underneath it.
This is exactly the sort of show I want to find at the Fringe. I walked in expecting a fun musical comedy about influencer twins arguing in therapy, laughed throughout, shed an actual tear and walked out having found my favourite show of the Edinburgh Fringe so far.
★★★★★
Under the Influence runs at Underbelly Bristo Square’s Dairy Room at 9.20pm until 30th August 2026, with no performance on 17th August.
Get your tickets Here!! https://www.edfringe.com/tickets/whats-on/under-the-influence
