Books penned by a legend, surprisingly becoming involved (9)
I believe the answer is:
entangled
'involved' is the definition.
(similar in meaning)
'books penned by a legend surprisingly' is the wordplay.
'books' becomes 'nt' (abbreviation for New Testament).
'penned by' is an insertion indicator.
'surprisingly' is an anagram indicator.
'a'+'legend'='alegend'
'alegend' anagrammed gives 'eangled'.
'nt' put into 'eangled' is 'ENTANGLED'.
'becoming' acts as a link.
(Other definitions for entangled that I've seen before include "snarled up" , "Involved in complications" , "Intertwined; entrapped" , "caught" , "Confusedly twisted" .)