The vessel is positioned beneath a large suspended rock, with a single spotlioght cast over the vase. 5 minutes before the performance, the lights are switched off and tension begins to build. Shane is to arrive at the venue around the 5 minute lights-off mark, to walk in amoungst the unsettled ongoers and set the rope on fire to begin the performacne.
The audience will not know exactly when the rope will give way and the rock plummet towards the vessel, but the inevitably of such will be present from the minute they walk into the room.