Disunity of odd blokes in sci-fi film (12)
I believe the answer is:
estrangement
'disunity' is the definition.
'odd blokes in sci-fi film' is the wordplay.
'odd' becomes 'strange' (I've seen this before**).
'blokes' becomes 'men' (I've seen this in other clues).
'in' means one lot of letters goes inside another.
'sci-fi film' becomes 'et' (I've seen this in other clues).
'strange'+'men'='strangemen'
'strangemen' placed into 'et' is 'ESTRANGEMENT'.
'of' is the link.
(Other definitions for estrangement that I've seen before include "lack of good relationship" , "Alienation" , "division" , "Result of splitting up" .)