Aidan Gould is remarkable as Tom, what are the joys and challenges of working with children?

TS: I can only think of joys. That they know the proper value of play. That they are up for the practical artifice of pretend; I've yet to meet a child of nine burdened with any concept of a method, or the pressure of taking their character home with them or all that displacement stuff. That they are in touch with the fun of making things up. That they are in no screwed-up battle with their dignity all the while. Altogether, in combination with the need for children to work restricted hours, it's grace.

There's an incredible amount of location work involved here and some striking locations -- do you prefer working on location?

TS: Possibly. It makes for a completely different texture to what you actually shoot, let's face it, and in the land of realness, or semi-realness, as in Julia, there is a kind of ease that comes with walking into real places surrounded by energies other than that of the film. Real walls, real pavement, real sky all help hold down the make believe and pin it into place.

Tilda Swinton in Julia

We're soon to see you in another Jim Jarmusch film, could you tell us a little about your character and the film itself?

TS: Pretty much nothing, I'm afraid. Isaach de Bankole wears sensational shiny suits. I wear a white wig and cowboy hat. Paz de la Huerta wears - mainly - not a stitch. We are all in Spain. Isaach meets us there, on an unexplained mission, as he does Bill Murray, Gael Garcia Bernal, John Hurt, Youki Kudoh and others. We hand him cryptic messages in matchboxes and expound on art, music, science, hallucinogenics and sex. My subject is cinema. Isaach keeps moving. It's a mystery story with a protagonist so calm, so opaque, that we can rest in his company - go along for the ride in blissful ignorance, perhaps even give up on impatience in the beauty of this landscape, under the umberella of this soundtrack. Credit crunch, eco-friendly, existential travel for the price of a cinema seat and minimal carbon footprint.