This paper examines the promise of science and its role in shaping research policy. The promise of science is characterized by expectations of science, which are embedded in promissory discourses that envision futures made possible through advances in promising science. Through a single case study of the origins of Genome Canada, the research was guided by the question: How did expectations of genomics shape the creation of Genome Canada? A conceptualization of discursive power and expectations of genomics storylines provide the (...) theoretical and analytical basis for an in-depth examination of the ideational effects and material impacts on research policy decisions over three years that culminated in the creation of Genome Canada. Expectations of genomics storylines functioned in a complex interplay of discursive practices and dynamics among diverse policy actors within a genomics discourse-coalition to produce a range of ideational and material impacts. The expectations of genomics storylines produced powerful genomics subject-positions from which policy actors perceived their interests, identities and preferences and gained agency, which led to various material impacts, such as mobilizing support and funding, coordinating activities and transforming Canada’s research policy framework. With the increasing importance of research policy to a range of broader policy priorities underpinned by expectations that science will resolve societal challenges and contribute to socio-economic benefits, this paper sheds light on how complex research policy decisions are made; it further contributes to understanding the role of promissory discourses in shaping those decisions. (shrink)