Novel, we hear, about university detective and bespectacled bachelor – not bad! (5,4)

'bad' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.

'novel we hear about university detective and bespectacled bachelor not' is the wordplay.
I cannot quite understand how this works, but
'novel' could be 'book' and 'book' is found within the answer.
'about' could be 'a' (abbreviation in Chambers) and 'a' is found in the answer.
'university' could be 'u' (abbreviation for university) and 'u' is found in the answer.
'detective' could be 'di' (Detective Inspector abbreviation) and 'di' is found within the answer.
'not' could be 'o' (I've seen this in other clues) and 'o' is located in the answer.
This accounts for all the letters.
This explanation may well be incorrect...

Can you help me to learn more?