Extract from revolutionary Hammett novel (4)
I believe the answer is:
emma
'novel' is the definition.
(I've seen this before)
'extract from revolutionary hammett' is the wordplay.
'revolutionary' says the letters should be written backwards.
'extract from' says the answer is hidden in the clue (I've seen this in other clues).
'amme' is hidden within 'hammett'.
'amme' backwards is 'EMMA'.
(Other definitions for emma that I've seen before include "Jane Austen's fourth novel (1815)" , "Ack -, a term for a.m." , "Title of novel by Jane Austen" , "Lady Hamilton or Lady Thompson?" , "novelist's work" .)