I would just like to point out that "a window to the west" is a clear reference to Gustav Meyrink's novel, "The Angel of the Western Window", which is based on the life of Dr Dee, the same alchemist as the Maiden song of the same title written by Dickinson (The alchemist, from the album The Final Frontier, 2010). Therefore, this is the most likely subject of the song.
I would just like to point out that "a window to the west" is a clear reference to Gustav Meyrink's novel, "The Angel of the Western Window", which is based on the life of Dr Dee, the same alchemist as the Maiden song of the same title written by Dickinson (The alchemist, from the album The Final Frontier, 2010). Therefore, this is the most likely subject of the song.
[Edit: I forgot the verse of the reference ]