In 2011, Year 9 science extension students at a regional Queensland secondary school participated in a ‘full’ scientific inquiry (US National Academy of Sciences, 2000), wherein they undertook plant growth trials to investigate the capacity of biochar, a finegrained charcoal, to enhance the nutrient quality of compost. The inquiry was planned and guided by their teacher and a scientist, who aimed to afford high-performing, junior secondary students an opportunity to work alongside a ‘real scientist’ and experience the ‘thinking and doing of science’ (Hume & Coll, 2010). Qualitative data emanating from semistructured interviews with nine students, as well as the teacher and scientist, revealed high levels of student engagement in the inquiry focus, given potential benefits of biochar as a combined system for soil improvement and carbon sequestration. Students reported working with greater accuracy and purposefulness as inquiry results were not predetermined and were to inform pilot research for the scientist’s doctorate. Quantitative data analysis revealed that students who participated in the biochar inquiry outperformed their science extension-level peers who did not participate in the inquiry, in both a state-wide science test and overall science grades. Findings of this study highlight positive outcomes to have resulted from the student–scientist partnership. At a time when the school science curriculum is failing to engage the majority of young people (Lyons, 2006), there is need for further research to evaluate the effectiveness of this strategy in enhancing student engagement and achievement in science in the compulsory years of schooling.