Epic poem in book, woeful novel (7)
I believe the answer is:
beowulf
'epic' is the definition.
(I've seen this before)
'book woeful novel' is the wordplay.
'book' becomes 'b'.
'novel' is an anagram indicator.
'woeful' anagrammed gives 'eowulf'.
'b'+'eowulf'='BEOWULF'
'poem in' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
(Other definitions for beowulf that I've seen before include "Old English epic poem" , "Germanic hero" , "Old English saga" , "[SCAN-DIN-AVIAN] poem" , "An old tale" .)