One with an important part in 'The Traitor's Return'
I believe the answer is:
star
'one with an important part' is the definition.
I know that 'part' relates to this answer.
'traitor's return' is the wordplay.
'traitor's' becomes 'rat's' (rat can mean a traitor).
'return' shows that the letters should be reversed in order.
'rats' reversed gives 'STAR'.
'in the' is the link.
Can you help me to learn more?
(Other definitions for star that I've seen before include "Famous person" , "Actor in a principal role" , "Heavenly light" , "may be a dwarf or a giant" , "Principal actor in a film" .)