THERE'S something unattractive about performers obsessed with the idea of performance. At best, they seem self-absorbed; at worst, they reduce every subject they touch to a smart ironic gesture. Lone Twin's Daniel Hit By a Train, playing at the Arches this weekend, is a show that pushes this risk to the limit. It not only chooses a poignant subject, in the stories of ordinary people who died during acts of extraordinary heroism, recorded on plaques in Postman's Park, London, it also subjects those stories to a scrutiny that begins with an irony of tone, and ends with a questioning of the very idea of self-sacrifice and heroism.

In the end, though – and despite some infuriating moments – this hugely inventive Brighton group succeed in saying something unsettling and profound about Victorian popular culture, and the way it sought to transform real human tragedy into sentimental public spectacle. There's an air of the music-hall about the whole show; and the mixture of the morbid, the macabre, and the desperately entertaining fits like a glove.

Meanwhile, in the basement, Glasgow-based group 12 Stars, with PM Music, present We're The Believers, a work-in-progress about religious cults. At the moment, the show consists of a 35-minute meditation on the doomed Branch Davidians, and on the Church of Scientology, with readings from the words of believers woven around an emerging pattern of synthesised music and minimal movement, and punctuated by a powerfully-written, poignant litany of positive psychological transformation. This version of We're the Believers is no more than a light-touch outline. But it's a work of obvious integrity, on a significant theme; and it's also mercifully free of those ironic theatrical "quotation marks" through which real meaning often struggles to make itself felt.