Hong Kong Garden had been a massive hit for them reaching #7 in the charts in the UK. It already showed that they were moving away from the Punk sound and the debut album whilst containing many of the songs that had steered them through Punk also held out a view that their music was going to be much bigger than Punk could ever hope to be.
Melody Maker had declared that "The Staircase (Mystery) hasn't anywhere near the commercial potential or immediacy of Hong Kong Garden, but nevertheless it's a great song. A sinister almost mesmerising tune, dominated by Siouxsie's unorthodox vocals – it grows and matures with each play."
It's funny looking at the lyrics to this all these years on from when it first came out because I didn't really have a clue what she was singing about then and 37 years later I still don't...Maybe that's The Mystery!
I love the B-side of this as well. They had already shown a knack for picking great cover versions (their version of Helter Skelter I think is the best cover of it...move along Bono!) and this one from the songbook of Marc Bolan worked really well for them.
The Staircase (Mystery) / 20th Century Boy - Siouxsie and the Banshees
Produced by Nils Stevenson
Released 23rd March 1979
UK Chart #24
A-Side: The Staircase (Mystery)
B-Side: 20th Century Boy