As part of a school project about local urban legends, four friends decide to explore an abandoned building scheduled for demolition in the coming weeks. While filming content for their video channel, they discover a door marked only with the number 404. The room does not appear on any official floor plan. At first, it seems like nothing more than an empty space, but as they continue exploring the surrounding hallways, the group begins to notice something is wrong. Corridors repeat themselves, doors lead back to the same places, and the path they came from slowly disappears. When one of the friends vanishes without a trace, the others must uncover the truth behind Room 404 before they disappear as well. Room 404 Incident is a found-footage horror short film that follows the recovered recordings from the phones and cameras left behind after the incident.