With Performative Topologies I introduce an ephemeral Diagrammatic Instrument. Prepared verbal prompts shape an interaction between several participants and a facilitator. The process is structured around open sharing of the memory of a meaningful object, and shifting between modes of engaging with this memory, individually and as a group. This generates personal movement sequences that are paired with a feedback projection, topologically modified 360-degree video streaming in real time. As particpiants jointly iterate their movements, attention doubles, performing and observing.