Production of films of upset people surrounded by spies (6)
I believe the answer is:
cinema
'production of films' is the definition.
'cinema' can be an answer for 'films' (I've seen this in another clue). I am unsure of the 'production of' bit.
'upset people surrounded by spies' is the wordplay.
'upset' says the letters should be written in reverse.
'people' becomes 'men' (men are people).
'surrounded by' means one lot of letters goes inside another.
'spies' becomes 'CIA' (Central Intelligence Agency).
'men' reversed gives 'nem'.
'nem' inserted inside 'cia' is 'CINEMA'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for cinema that I've seen before include "Local form of language" , "multiplex, perhaps" , "place for pictures" , "Silver screen" , "Motion pictures" .)