My cousin and I were fending off the Flood in one of the later levels of Halo. So, after we killed them all, we found ourselves on a platform and grenades all around us (some Flood got WAAAY to close). Well, one of us had the brilliand idea to throw a grenade at the bodies (or there was one left) and the grenade set off all the others and killed us, and we had to do the entire thing again (did I mention we had to gothrough at least thrity Flood, including the ones on the platform?)