At that point the theatre is rebuilt (7)
I believe the answer is:
thereat
'at that point' is the definition.
(I've seen this before)
'theatre is rebuilt' is the wordplay.
'is rebuilt' is an anagram indicator.
'theatre' with letters rearranged gives 'THEREAT'.
'the' acts as a link.
(Other definitions for thereat that I've seen before include "At that place" , "On account of that" , "At that point" , "Theatre (anag)" .)