Climate fiction (cli-fi) is widely assumed to have cognitive value for student and teacher understanding of climate change, often attributed to automatic mental processes based on trial and error. This study argues its cognitive value lies in systematic mental actions that transform cli-fi into school science problems for educational benefits to students and teachers. A guide, grounded in agentive activity theory, was developed to orient these actions and tested with three secondary school biology teachers. The participants worked with two excerpts from “The Ministry of the Future” by Kim Stanley Robinson and another adapted from the article “Scientists at odds over wild plans to slow melting glaciers” by Hannah Richter. Think-aloud and retrospective interviews were used. Three key stages emerged: narrative immersion in cli-fi, problem structuring and editing/correction. The findings indicate that the guide supports teachers’ agency and self-regulation during the transformation process, although there is a limitation related to teachers’ content knowledge. It is concluded that the guide enhances teachers’ control over cli-fi transformations, and the educational cognitive value of cli-fi may reside in agentive activity.