Story's conclusion on stage (6)
I believe the answer is:
legend
'story's' is the definition.
(legend is a kind of story)
'conclusion on stage' is the wordplay.
'conclusion' becomes 'end' (end is a kind of conclusion).
'on' means one lot of letters go next to another.
'stage' becomes 'leg' ('leg' can be a synonym of 'stage').
'end' after 'leg' is 'LEGEND'.
(Other definitions for legend that I've seen before include "Celebrity" , "Story of mythical beings or events" , "King Arthur" , "Very famous member's death" , "The story of Achilles, say" .)