King and scoundrel taken in by simple story (9)
I believe the answer is:
narrative
'story' is the definition.
(I know that story can be written as narrative)
'king and scoundrel taken in by simple' is the wordplay.
'king' becomes 'R' (abbreviation for rex, king in Latin).
'and' means one lot of letters go next to another.
'scoundrel' becomes 'rat' (rat can mean a nasty person).
'taken in by' indicates putting letters inside.
'simple' becomes 'naive' (similar in meaning).
'r'+'rat'='rrat'
'rrat' going inside 'naive' is 'NARRATIVE'.
(Other definitions for narrative that I've seen before include "Story line" , "Tale" , "Story recounting events" , "Report" , "Account of connected events, a story" .)