A zombie apocalypse. I was walking with some friends along a sidewalk, armed with sticks or whatever improvised weapons we could find. One of us stayed behind. As we were walking this guy tried to catch up, so we waited for him while chatting. My consciousness was separated from my body and I saw this as a scene: he had converted into a zombie and surprised us, we reacted just in time to knock him out before he could bite any of us.