Agency interested in aliens - one can blink strangely (3,2,5)
I believe the answer is:
men in black
'agency interested in aliens' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'one can blink strangely' is the wordplay.
'one' becomes 'me' (a setter might use 'one' to humourously mean 'me').
'strangely' indicates an anagram.
'can'+'blink'='canblink'
'canblink' anagrammed gives 'ninblack'.
'me'+'ninblack'='MEN IN BLACK'
Can you help me to learn more?
(Other definitions for men in black that I've seen before include "Guardians of those disguised as human" , "referees, maybe" .)