Non-existent location present at this moment? (7)
I believe the answer is:
nowhere
'non-existent location' is the definition.
(I've seen this before)
'present at this moment?' is the wordplay.
'present' becomes 'here' (both can mean in attendance).
'at' says to put letters next to each other (I've seen this in other clues).
'this moment?' becomes 'now' (the present moment).
'here' after 'now' is 'NOWHERE'.
(Other definitions for nowhere that I've seen before include "Non-existent location" , "News from - (William Morris)" , "remote location" , "unlikely to be found?" , "One present is not" .)