Remake heavenly with this sad old film (3,4,8)
I believe the answer is:
the lady vanishes
'old film' is the definition.
(I've seen this before)
'remake heavenly with this sad' is the wordplay.
'remake' indicates anagramming the letters.
'with' says to put letters next to each other.
'heavenly'+'this'+'sad'='heavenlythissad'
'heavenlythissad' is an anagram of 'THE LADY VANISHES'.
(Other definitions for the lady vanishes that I've seen before include "Hitchcock film" , "woman goes missing" , "Once prepared for screening" , "Old film" .)