The Subplot: A Hyperfixation on the Titan Submersible - Edinburgh Fringe Festival 2026

​Based on the almost standing-room-only basement on a Saturday afternoon, “Captain” Sophie Smyth isn’t the only person still obsessed with the OceanGate Titan submersible. Decked out in her authentic OceanGate cap and homemade boiler suit, and equipped with a laptop and Logitech F710 controller, Smyth takes us through the timeline of the infamous implosion in one of the best multimedia presentations I’ve seen at the Fringe. It is funny, strange and wonderfully immersive, pulling us into what the inside her brain must look like too.  It’s a genuinely brilliant piece of immersive theatre with the Summerhall basement setting acting as a sub making us feel part of her sub team too.

But for Smyth, the story didn’t end when the memes stopped. What began as an interest became a hyperfixation, and that hyperfixation becomes the beating heart of the show. As an autistic and ADHD performer with her own experiences of mental health too, Smyth uses the Titan disaster as a way of exploring something much more personal: what happens when your brain latches onto something and refuses to let go? The subject may be ridiculous, but the experience of obsession is anything but.

The show’s most fascinating turn comes when Smyth starts to draw a line between her own neurodivergent relationship with the Titan and the billionaires who willingly climbed inside it. Why were they so attracted to this tiny submersible? What made them want to go somewhere so dangerous, so inaccessible and so far outside the ordinary? Smyth doesn’t suggest that their experiences are the same as hers, but instead asks whether there might be something recognisable in the compulsion itself and the desire to pursue an interest beyond the point other people could possibly understand.

Smyth takes something that could easily remain an internet curiosity and uses it to examine neurodivergence, hyperfixation, mental health and the strange ways our brains can find meaning in things other people simply don’t get. There is real vulnerability underneath the jokes, particularly in the recognition that an obsession can be both comforting and consuming.

Lee Hutchison

5/5

Runs until August 31st at Summerhall