Perfect theatre almost hosts exciting premiere (5)

I believe the answer is:

dream

I'm a little stuck... Click here to teach me more about this clue!

'perfect' is the definition.
(I've seen this before)

I can't explain the remainder of the clue.

(Other definitions for dream that I've seen before include "Bedroom vision?" , "Nocturnal vision" , "Vision - very pleasant person" , "Nocturnal fantasy" , "Sleeping thoughts" .)

I've seen this clue in The Daily Express.

Want a hint initially instead of a full solution? Install my app