As soon as you enter the performance space, they are there. Figures swoop on you, chattering in a language you don't understand, guiding you to a seat. You feel pecked at, part of a gang you didn't know you had signed up to. You have unwittingly become part of the flock.
A second collaboration between Cardiff-based Earthfall and Polish company Theatre Association Chorea, this is an imaginative, radical reworking of Aristophanes' comedy The Birds, in dance, physical theatre and song. Ostensibly it is about a group of rebels who attempt to create a new, uncorrupted society halfway between humans and gods. But what works best is the portrayal of group psychology: how outsiders are regarded, how we remove ourselves from the flock and then want more than anything to be part of it again.
Watching the flock and its continual unravelling and reforming, you do feel like an outsider; this is clearly intentional, as the group also sing in Polish, with the mysterious words acting like a barrier between the group and the audience. This limits how involved you can get, but it also underlines the central theme of inclusion versus exile.
There are moments of violence and chilly disregard, especially when members of the group break off in pairs. From here, as a couple repeatedly, violently collide, the flock looks a gentle, nurturing place to be. It isn't, of course - but the allure of a clearly defined pecking order is unmistakable.
· Until November 17. Box office: 08700 402000.
