What design fiction is seems to be a matter of debate whilst how design fiction accomplishes its feats lacks attention among the design research community. This research program focuses on how people engage with a fictional story world through interactive artefacts or in other words, how disbelief is suspended when design is employed as an ingredient that embodies some aspects of a fictional narrative. In order to explore this, we invited four participants to interact with a purposefully designed prototype: the Digital Dreamcatcher. The Digital Dreamcatcher is a fictional device that interprets dreams by printing personalised poetry. Based on qualitative analysis from interviews with participants, we propose a preliminary conceptualisation of design fiction as system, rather than simply an object or a story. Looking at our data from the perspective of design fiction as a system also allowed us to identify “suspension of disbelief” only in autopoietic design fictions. These are design fictions able to create, extend and maintain themselves. This insight might enable practitioners using or considering the use of design fiction to look at their current or prospective work from a new perspective.