Something brewing in the state apartments (3)
I believe the answer is:
tea
'something brewing' is the definition.
(I've seen this in another clue)
'in the state apartments' is the wordplay.
'in' indicates a hidden word.
'TEA' is hidden within 'state apartments'.
(Other definitions for tea that I've seen before include "Drink made from leaves" , "Afternoon meal; drink" , "A light meal - eat up" , "Beverage; meal" , "Common drink" .)