Servant must return before four in this city (3,4)
I believe the answer is:
tel aviv
'this city' is the definition.
(Tel Aviv is an example)
'servant must return before four' is the wordplay.
'servant' becomes 'valet' (valet is a kind of servant**).
'must return' says the letters should be written backwards.
'before' means one lot of letters go next to another.
'four' becomes 'iv' (roman numeral).
'valet' written backwards gives 'telav'.
'telav'+'iv'='TEL AVIV'
'in' acts as a link.
(Other definitions for tel aviv that I've seen before include "Israel's administrative capital" , "Middle Eastern city" , "Capital of Israel" , "Major city of Israel" , "City with vile vat for more of 13 Across" .)