Denouement that's heart-rending? Not half (6)
I believe the answer is:
ending
'denouement' is the definition.
(a denouement is the end of a story)
'heart-rending? not half' is the wordplay.
'ENDING' is hidden within the letters.
But, I am not sure how the hidden word is indicated.
'that's' is the link.
Can you help me to learn more?
(Other definitions for ending that I've seen before include "Stopping" , "Termination, conclusion" , "Close - conclusion" , "Finale" , "Putting a stop to" .)