Great stories with endings switched to create excitement (5)
I believe the answer is:
spice
'excitement' is the definition.
(thesaurus)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for spice that I've seen before include "Something providing excitement" , "Eg, cinnamon" , "Pungent flavouring" , "eg Mace, ginger, Posh" , "Flavouring substance" .)