In this scene, mysterious foe is revealed (5)
I believe the answer is:
enemy
'in this scene mysterious foe is revealed' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'in this scene mysterious' is the wordplay.
'in' indicates the answer is hidden within the clue.
'ENEMY' is hidden within 'this scene mysterious'.
Can you help me to learn more?
(Other definitions for enemy that I've seen before include "Time" , "Foe, adversary" , "Opposing force" , "Hostile opponent" , "Armed adversary" .)