The most common and most likely answer to this crossword clue is the 3 plus 10 letter word THE GO-BETWEEN
I've seen this crossword clue in Financial Times
T
H
E
G
O
-
B
E
T
W
E
E
N
Buddy explains!
The straight part
We know that "novel" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case novel = the go-between.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.