Not surprisingly, after a month of this, Riley and Heglund, and their co-star Kristen Stewart, who plays Dean's wild-child girlfriend, Marylou, were desperately keen to move on. Which was probably Salles's intention. Over the subsequent six months they properly took to the highway. "Walter wanted us to be as bonded as possible. We had to wrap Kristen's stuff in the first three months so we were flying all over the place to get the right weather," Riley recalls. "We went down to Patagonia for four days for the snow, and then Louisiana, 100% humidity, then Arizona, then Mexico, then Calgary, then we finished in San Francisco… "