At a party I went to a couple of years ago, somebody insisted on showing everyone the trailer of The Human Centipede. Before this I was quite happily unaware of the 'torture porn' genre, and my reaction to seeing a snippet of it was a mixture of disgruntlement and disgust. It left me wondering whether subject matter like it would soon be the norm, whether people are just getting more and more inured to the depiction of violence.

But, as so often seems to be the case, the Romans got there first. Seneca was writing about seriously graphic and disgusting things way before Eli Roth or Tom Six, and his rendering of the Thyestes myth - wherein children are murdered, butchered, cooked and plated up as their unknowing father's dinner - revels in gruesome particularity; just reading it put me off my lunch.

I tell this to Rachel Cunliffe and Phil Howe, who are directing an adaptation of the play at the ADC this term. They laugh (only a little bit evilly) before Phil quotes one of the play's many grisly lines with relish. Rachel, who is a classicist, explains that overt gore is rarer in ancient Greek plays than in Roman ones; violence is usually reported rather than staged. 'Seneca's tragedy takes it up a notch,' she says. 'He writes the exact details of what Atreus does to the children and exactly how he cooks them and how they get eaten. I think that level of detail is there to shock you, but also to make you laugh'. 'It's very easy to make it funny', adds Phil. 'Violence that brutal just takes on an air of absurdity'. So far, so Quentin Tarantino. When I ask the pair why they think revenge plays continue to be put on and why revenge continues to interest people, Phil replies that it's just as central to the human psyche as it has always been, it's just that 'people now use the word justice instead'.

They are quick to clarify that this is an adaptation of the original. The pair have been working from a 1920s translation ('no rights to pay!'), half of which they've rewritten in modern language, whilst trying to stick as closely as possible to the essence of the original in the process. Despite this proximity, hearing an actor using words you've written can be a strange experience, and Phil attests that 'when you hear the way some of the actors read lines you think, wow, that's not how I saw it, but it really, really works.'

Having a classicist onboard has been a real asset in translation, and in other aspects too; when I quiz Rachel on what to make of the chorus, she has a refreshingly clear answer: 'they're meant to observe what's going on and to reflect on it, but they are also completely ineffectual, they can't interfere. They can and do get what's going on completely wrong; often they are standing there saying 'oh wow, isn't everything wonderful' while the audience is left wondering why they can't see what's in front of them. In this way, they're a little bit of comic relief, but also a little bit sad'.

Rachel and Phil are relatively inexperienced directors; Rachel has never directed before while Phil has directed just one other play. What have they made of the experience? 'It's a huge shock when you first direct,' Phil tells me. 'You're hit by a wall of things to do that you didn't even realise existed. As an actor, you get your rehearsal schedule, you learn your lines, and the show just happens.' Rachel is 'surprised at how chilled out it's been, and at how I can see things that don't work in a scene, and devise ways to make them work when I'm not an actor at all.' She is vehement in recommending anyone who's always wanted to try directing but has always been scared to, to 'just do it. You can't learn how to do it until you're actually doing it.'

Both directors are brimming with enthusiasm and ideas. I'm intrigued to see this production, and to see whether the central conceit really does become blackly comic as well as gross. When I ask is them if queasiness is a reaction they'd like their audiences to have, the pair toy with the idea of handing complementary pigs in blankets to the audience upon entry. 'Too far', they quickly decide. Probably wise.