Agency plan to retain English Bible (12)
I believe the answer is:
intervention
'agency' is the definition.
(I've seen this before)
'plan to retain english bible' is the wordplay.
I cannot really understand how this works, but
'english' could be 'e' (abbreviation) and 'e' is located in the answer.
'bible' could be 'rv' (Revised Version, revision of King James Bible) and 'rv' is located in the answer.
'plan' could be 'intention' (I've seen this before) and 'intention' is present in the leftover letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for intervention that I've seen before include "Mediation; interference" , "Agency" , "Mediation, stepping-in" , "Action taken to improve a medical disorder" .)