Story has Silver in it (4)
I believe the answer is:
saga
'story' is the definition.
(a saga is a long story)
'silver in it' is the wordplay.
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'in' means one lot of letters goes inside another.
'it' becomes 'sa' (SA can mean sex appeal, as in 'it').
'ag' put into 'sa' is 'SAGA'.
'has' is the link.
(Other definitions for saga that I've seen before include "Epic - legend" , "long series of events" , "Account of great heroism" , "Epic story" , "Epic tale" .)