Drunk is serene in other-worldly atmosphere (8)

I believe the answer is:
eeriness
'atmosphere' is the definition.
(I have seen 'Ghostly atmosphere' mean 'eeriness' so perhaps 'atmosphere' could also mean 'eeriness')
'drunk is serene' is the wordplay.
'drunk' is an anagram indicator.
'is'+'serene'='isserene'
'isserene' is an anagram of 'EERINESS'.
'in other-worldly' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for eeriness that I've seen before include "Strange and frightening quality" , "'Weirdness, scariness (8)'" , "Is serene (anag.)" , "Horror movie featuring such" , "Weird quality" .)
