Some paintings do go back in the gallery (4)
I believe the answer is:
gods
'gallery' is the definition.
(I've seen this in other clues)
'some paintings do go back in' is the wordplay.
'in' says the answer is hidden in the clue.
'back' is a reversal indicator.
'sdog' can be found hidden inside 'some paintings do go'.
'sdog' back-to-front is 'GODS'.
'the' acts as a link.
(Other definitions for gods that I've seen before include "Gallery of a theatre" , "Superhuman beings" , "Area of theatre" , "objects of worship" , "Supernatural beings" .)