The line "Shadows fell from trees" descends (one of the vocal parts is D D C Bb A), so there's a musically representation of that falling.
More interesting, though, is the last section of lyrics. I'm not completely sure of my transcription, but I think it's:
"Enter in, all ye who seek to find within"
As the plaque said on the last door
I think this is meant to be the inverse of the inscription above the Gate of Hell in Dante's Inferno: "All hope abandon, ye who enter in!" (canto III, line 9). If nothing else, it's a similar image.
