Brewing, in the wind (5)
I believe the answer is:
afoot
I believe this clue is a double definition.
'brewing' is the first definition.
(I've seen this in another clue)
'in the wind' is the second definition.
(I've seen this in another clue)
(Other definitions for afoot that I've seen before include "Progressing, in operation - like Sherlock Holmes's game" , "Going on" , "Brewing" , "in the air" , "Under way (like hunted game?)" .)