"Borders are inherently violent". It's a sentiment that seems to be coming up time and again at the Fringe, with borders one of this year's big ‘themes'. Daniel Bye's show, directed by Alex Swift, is a pleasingly equivocating look at activism and resistance, the lengths we can or should go to disrupt unjust systems. It doesn't offer any packaged conclusions, but it does needle and niggle.

Bye was inspired to make a show about Edward Shorter, an elusive (in fact, invented) protester-cum-performance artist who scripted political interventions. Bye has an accessible chirpiness: he's no zealot, just a well-meaning middle-class chap wanting to make a difference. Aren't we all…

He plays Jenga with a volunteer from the audience while they discuss what they're afraid of. Bye's biggest fear is crowds, and so he's erected a barrier around the stage. His own border. This interaction, we're told, follows one of Shorter's ‘Instructions for Border Crossing' scenarios – only Shorter suggests it be staged at a real-life border until one of the players is dragged away or killed… Of course, the amiable Bye doesn't want anything quite as extreme as that.

In fact, he's not really that onboard with Shorter's demanding commitment to the cause. Shorter lived as a homeless person, a total rejection of capitalism and inequality; but Bye, with a somewhat unconvincing naivety, explains that he'd rather the less fortunate became more comfortable. Champagne socialism, as long as there's champagne for all! Later, he'll discuss owning property in the same way, with a slightly petulant defensiveness. The audience winces; we're also all (probably) more Bye than Shorter, even if we like to think we're radical.

Actually, the audience when I watched may not have considered themselves very bold at all. The show asks for regular volunteers, who identify as having a particularly admirable quality – braveness, tenacity, the ability to stand up to authority – to go onstage, where Bye gently questions them about how they manifest this. Their day-to-day examples of courage and resistance are revisited in a powerful final conclusion to the piece. Thankfully, even given the reluctant involvement I witnessed, the conceit still worked.

These interactions are intermingled with narrated scenes about a 12 year-old girl, an activist also inspired by Shorter. She really lives this stuff. She wants to "reveal the complacency of the comfortably seated". She's ditched her passport and is trying to illegally cross back into Britain in a truck. There's a sly ambivalence towards both her extremism and Bye's dilettantism: both forms of activism are prodded and found ridiculous. There's something almost offensive about putting yourself needlessly through others' genuine hardship – but isn't there something also off about trying to change the world without it costing you anything?

The audience is lightly implicated in all this. We help act out Shorter's other instructions, reading projected scripts aloud. We become border guards, issuing aggressive demands. We don't have to speak the words – but most of the audience does.

To be honest, this attempt to implicate us is a little tired; if you're told to do something in a show, you do, not because you're a monster but because you're polite. Just another example of the complacency of the comfortably seated? Not so much – obediently reading a script really isn't equivalent to inflicting or sanctioning violence. Still, it does neatly parallel with Bye's story, in which he becomes an undercover border guard at the very detention centre the 12 year-old girl is held in. How complicit is he here – he's just playing a part, right?

The voices of the audience volunteers come back for a big finish, and Instructions for Border Crossing ultimately ends on a positive – maybe even over-optimistic – note. It suggests, perhaps, that we don't have to be extreme activists: the capacity for change is in all of us, every day.

Instruction for Border Crossing runs at Summerhall until 26 August then tours.

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