Attending a theatre but leaving at once? Actually twice (4)
I believe the answer is:
here
'attending' is the definition.
(I've seen this in another clue)
'a theatre but leaving at once? actually twice' is the wordplay.
I cannot really see how this works, but
'at' could be 'her' (I've seen this in other clues) and 'her' is located in the answer.
A single letter 'e' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
(Other definitions for here that I've seen before include "On this spot" , "In attendance" , "final clue?" , "To hand" , "At this stage" .)