Relate saga's end very quietly, sure to forget chapter (9)
I believe the answer is:
appertain
'relate' is the definition.
(I've seen this before)
'saga's end very quietly sure to forget chapter' is the wordplay.
I cannot quite see how this works, but
'quietly' could be 'pp' (musical abbreviation for pianissimo) and 'pp' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for appertain that I've seen before include "Bear on" , "Concern" , "Belong, relate (to)" , "Be relevant to" .)