Rest in the back of James’ operating room (6)
I believe the answer is:
repose
'rest in' is the definition.
(thesaurus)
'back of james' operating room' is the wordplay.
'back' shows that the letters should be reversed in order.
'of' indicates a hidden word.
'esoper' can be found hidden inside 'james operating room'.
'esoper' back-to-front is 'REPOSE'.
'the' acts as a link.
(Other definitions for repose that I've seen before include "Quiet restfulness" , "peace" , "place" , "State of tranquillity" , "take it easy" .)