She's back in the scene right on cue (5)
I believe the answer is:
irene
'cue' is the definition.
Both the definition and answer are singular nouns.
Perhaps you can see a link between them that I can't see?
'she's back in the scene right' is the wordplay.
'she's back' becomes 'ire' (I can't explain this - if you can you should give a lot more credence to this answer).
'right' suggests the final letters (the letter on the right of the word).
The last letters of 'in scene' are 'ne'.
'ire'+'ne'='IRENE'
'on' is the link.
Can you help me to learn more?
(Other definitions for irene that I've seen before include "Girl's name; Soames Forsyte's first wife" , "woman" , "In Greek mythology, the goddess of peace" , "One can find a girl in Ree" , "- - Handl, actress" .)