Involved tale about one in the end (8)
I believe the answer is:
entailed
'involved' is the definition.
(I've seen this in another clue)
'tale about one in the end' is the wordplay.
'about' is an anagram indicator.
'one' becomes 'i' (Roman numeral).
'in' is an insertion indicator.
'tale' anagrammed with 'i' can make 'taile'.
'taile' inserted into 'end' is 'ENTAILED'.
(Other definitions for entailed that I've seen before include "This property can't be sold" , "settled on designated heirs" , "It's involved" , "Made necessary by date-line" , "Needed" .)