This page is a theory for floor 4 of Doors.
New Feature
Moving train doors will spawn during the Seek chase in the Station, a new location, and Dupe's doors will have trains ramming you and then Dupe jump-scares you.
New Locations
Doors 301 - 325 is the Station where the first Seek chase happens, doors 326 - 346 is the Tracks, doors 347 - 350 is the Large Train, 352 is the Jeff shop like always, and the rest of the journey are random generated rooms.
New Entities
The new entities are Silence and The Howlers. To survive Silence, you mustn't make a sound, and Silence can hear the echos of your heartbeat inside the lockers. Silence only reacts to audio cues and Silence hates The Howlers. The Howlers act similarly to the Gloombats and are loud spirits making dog howl noises. If you don't make a sound, The Howlers will instantly kill the player.