the agent ("you") is on a trolley, a fast-moving cart that can only run on a track. it is not an automobile that can be driven off the edge of a road. it must stay on a track. ahead of the agent, five people are standing on the track, where the trolley will run over them and kill them. the agent has no way to stop the trolley. the only thing the agent can do is throw a switch to make the trolley change onto a different track. on this second track, there is one person. none of the six people have time to move out of the way.