If I had to describe Lucy Prebble’s The Effect in a single sentence, I’d likely describe it as an existential crisis distilled into theatrical form. Printed on the front of the program is a quote from the play: ‘I can tell the difference between who I am and a side effect’. Unfortunately for the play’s characters, the narrative makes every effort to contradict this, to the point that the quote’s mere placement on the program almost comes across as a mocking gesture. For The Effect presents a scenario where love, identity and free will all exist in a state of ambiguity. Are we slaves to the physical processes of our own bodies? And if so, is this something we should be horrified by, or merely accept?

The narrative initially focuses on Tristan (Ashley Hunt) and Connie (Jess Reilly), two very different personalities brought together as test subjects in a medical trial for a new anti-depressant. This set-up is quickly complicated when the two fall madly in love with each other and become uncertain as to whether their feelings are genuine, or merely the result of the drug interfering with their brain chemistry. Even more complications arise when Dr Lorna James (Alison Stibbe) and Dr Toby Sealey (Matt Blurton) begin to debate the implications of these results, whilst also bringing their own emotional baggage and biases to the proceedings.

Frustratingly, I can’t write too much about the narrative since it’s difficult to describe without some serious spoilers, which is a shame because the story is thoroughly compelling and deserves detailed discussion. All I can reveal is that there are plenty of twists and turns that left me in a state of continuous suspense and surprise throughout. These, combined with the deft application of tragedy and comedy ensured that the narrative was one of the strongest elements of this production.

Which is saying a lot, considering how consistently impressive the acting was. While I was familiar with the impressive abilities of Alison Stibbe and Matt Blurton from Ronin Theatre’s previous production, Collaborators, Ashley Hunt and Jess Reilly were equally impressive. This was particularly essential, since the minimalist stage design ensured that much of the responsibility for conveying a convincing environment lay with the actors, and how they interacted with each other and the limited props at their disposal. Ultimately, each performance was captivating.

There is only one piece of criticism I can level at The Effect, but whether or not you consider it to be a deal breaker is entirely down to personal preference. Whilst I was impressed by the play’s dialogue and complex themes, I was slightly less impressed by its portrayal of medical trials. Without spoiling any specific events, there were clearly at least a couple of moments in the play when the medical trial should have been called off. Even accounting for the possibility of human error, the fact that the narrative was allowed to progress as far as it did, is frankly bizarre. And I’m speaking as someone with no experience in the medical field. Then again, perhaps my limited knowledge of the subject is the only reason why this was largely a non-issue for me. Therefore, be warned: if these kinds of details do bother you then this play might drive you insane.

The Effect is an excellent piece of theatre. Part love story, part existentialist musing on the relationship between body and consciousness, with enough comedic elements thrown in to balance the bleaker moments. I thoroughly recommend you buy a ticket if you can.