Unexpected development in dance (5)
I believe the answer is:
twist
I believe this is a double definition.
'unexpected development' is the first definition.
(I've seen this before)
'dance' is the second definition.
(I know that twist is a type of dance)
'in' is the link.
(Other definitions for twist that I've seen before include "Misquote - pervert" , "Intertwine, contort" , "One wanting more" , "Spiral" , "Wind around like Dickens' Oliver" .)