Lyric discussion by Asshole246 

I love this song, because it's so cheesy from Brad and Janet's pov but so vital from RiffRaff's.

For Brad and Janet, they're like having this romantic walk in the dark rainy night toward this place where there's a beacon of warmth awaiting them. The irony of the lyric 'Over at the Frankenstein Place' is completely lost on them it seems. Given Rocky Horror's pop culture b-movie fetish for everything from King Kong to Flash Gordon and the Invisible Man, etc, the name 'Frankenstein' should reasonably instill some caution in the approaching travelers. The chorus essentially warns the couple that, yes, there is a light in the dark, but that light is situated in Frankenstein's Castle, where monsters dwell. They're heedless and innocent though so they walk right into the dragon's mouth.

On the other hand is RiffRaff, for whom I think this song provides an actual bit of backstory. We know when Frank and Magenta and RiffRaff arrived on Earth from their home planet, Frank'n'furter immediately started philandering with Eddie and Columbia. RiffRaff, based on these lyrics, immediately got hooked on drugs, morphine specifically:

"Flow Morphia slow, let the sun and light come streaming into my life".

Morphia is an antiquated synonym for morphine. Given that Eddie was a bit of a scumbag and Columbia was Eddie's girlfriend, it's probable that they were the ones who got RiffRaff hooked and also the ones who failed to keep him in ready supply but that might be a stretch.

I like to think that RiffRaff never getting his drugs is what really led to his betrayal of Frank'n'furter and Frank's and Rocky's deaths. This is possibly backed up by the some of the first lyrics in 'Sweet Transvestite' being:

"How do you do I see you've met my Faithful handyman He's just a little brought down because When you knocked He thought you were the candyman..."

Candyman in this context meaning drug dealer. The next lyrics could be interpreted as Frank addressing RiffRaff as much as Brad and Janet:

"Don't get strung out By the way I look..."

'Strung out' being a (now cliche?) term for painkiller withdrawal. Rocky Horror was first and foremost about sex, drugs and rock n roll and all that.

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