Natural desire somehow to pen second novel (8,6)
I believe the answer is:
treasure island
'novel' is the definition.
(I know that Treasure Island form of creative work novel)
'natural desire somehow to pen second' is the wordplay.
'somehow' indicates anagramming the letters.
'to pen' indicates putting letters inside.
'second' becomes 's' (common abbreviation).
'natural'+'desire'='naturaldesire'
'naturaldesire' anagrammed gives 'treaureisland'.
'treaureisland' going around 's' is 'TREASURE ISLAND'.
(Other definitions for treasure island that I've seen before include "Classic adventure story" , "Long John Silver tale" , "work" , "Tale of adventure" , "Book by Stevenson" .)