The telling of stories that aim to connect with audiences across national and international borders is a defining characteristic of screenwriting and script development in international film co-productions and collaborations. As the Chinese-Australian writer-director Pauline Chan says of writing and developing 33 Postcards (2011), the second official China-Australia feature film co-production, she set out to make a film that was “many voiced”, seeking “[t]o meld two cultures, two storytelling traditions, two talent pools… two very different business environments” (Chan 2012). But how do screenwriters partner up to tell stories that are “many voiced”—transnational stories that meld cultures and storytelling traditions to cross borders and reach multiple audiences? This chapter contributes to the field of screenwriting research by applying and interweaving theories from the emerging academic fields of Script Development and Transnational Film theory, to understand what is important in telling a transnational story in the script development of two Australian international collaborations. The first case study is of the aforementioned official Australia-China co-production, 33 Postcards by Pauline Chan; and the second case study is of the Venice Biennale College-funded Strange Colours (2017) by Russian-born Australian writer-director Alena Lodkina.