They have been with you all along.
The fourth door is a knot in a rope that hangs from nowhere. You untie it with a promise you know you will break. the nine doors to the kingdom of shadows
Before the first door, you forget your name. It is a slab of obsidian set into a hill of skulls, and it opens not with a key but with a silence you must hold in your chest for nine heartbeats. They have been with you all along