This article reports on the findings of a research project whose aim was to support and enhance the teaching of risk at Key Stage 4. An innovative and cross-curricular approach has been used, based on modelling socio-scientific issues using new technological tools, designed specifically to enable the consideration of ethical and social issues, building personal value systems alongside quantifiable mathematical models. By interacting more deeply with interdisciplinary knowledge, the aim is that mathematics and science teachers can be empowered to develop meaningful activities around the concept of risk. A key component of the research has been that pairs of teachers--one of mathematics, one of science--from the same school work together to explore possibilities of cross-curricular working, and also become involved with the design work of the project. The understanding of risk incorporates concepts which go beyond substantive science or probability into affective and social science domains. To address this problem, the researchers have designed--in collaboration with teachers--computer-based "microworlds" in which teachers can explore and interrogate their knowledge of risk, including pedagogical knowledge. Using these "microworlds," the intention is for teachers to increase their confidence in teaching about risk, and to enthuse students, particularly with regard to probability. (Contains 3 notes.)