Me on the Train

This is a train that carries thirty lives. People who get off at each station are either alive or dead. The announcement calls for survival, but the conductor announces the name of the next station... A car accident in Linze City resulted in 30 people being seriously injured and comatose. The life-sustaining equipment in the intensive care unit was beeping, and the noisy living beings outside the house couldn't help crying. The police who woke up looked for the truth everywhere, but accidentally discovered that the number and gender of the people who got off the station in the dream were actually linked to reality... Reality and dreams alternate. Who is the final murderer? Can death really bring relief to everyone? (It looks a bit like an infinite flow, and there is a high probability that there will be no emotional line for the protagonist.)