This paper reflects on the role of Human-Computer Interaction (HCI) research and practice both in addressing and exacerbating current environmental crises. Observing a discrepancy between the urgency of these crises and the attention they receive in HCI, we generated and analysed twelve fictional narratives that speculate about what it could mean if HCI prioritized environmental sustainability. This exercise helped us identify possible strategies towards this aim through addressing HCI practices such as conferencing, teaching and research. These strategies include building on existing meso-level initiatives in the community, reorienting reviewing processes, practising prefiguration, being mindful of diverse perspectives, and adding a touch of humour. Publishing our set of narratives in the form of a book of fairy tales alongside this paper is one step in that direction. We hope the book and the paper contribute to raising and nuancing the topic of (un)sustainability in HCI.