Boy's story enthralling tot (6)
I believe the answer is:
laddie
'boy's' is the definition.
(laddie is a kind of boy)
'story enthralling tot' is the wordplay.
'story' becomes 'lie' (I've seen this before).
'enthralling' is an insertion indicator.
'tot' becomes 'add' ('add' can be a synonym of 'tot').
'lie' placed around 'add' is 'LADDIE'.
(Other definitions for laddie that I've seen before include "Child" , "Scottish boy" , "(Scots) boy" , "Sonny" , "Youngster" .)