Once you've left, there's no coming back to exactly where you were. Mark Aitken and guests walk and talk and discover that things will never be the same again. This month: Mark Aitken and Jonty Sale discuss and muse over sounds relating to what is over, under, inside and through their experiences of entanglements with nonhuman forms when making photographs. Their whole point of no return is marked by the opening of a joint exhibition called 'In Discrete Dialogue' at Ken Artspace on the 5th October as part of PhotoMonth, London.