Detective losing extremely versatile ringleader (10)
I believe the answer is:
instigator
'ringleader' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for instigator that I've seen before include "One who initiates (something)" , "One setting off" , "prime mover" , "Stirrer" , "starter" .)