Everything is plain at the end of the emergency (3,5)
I believe the answer is:
all clear
'the emergency' is the definition.
Although both the answer and definition are singular nouns, I cannot see how they can define each other.
'everything is plain at the end' is the wordplay.
'everything' becomes 'all' (all things).
'is plain' becomes 'clear' (similar in meaning).
'at the end' says to put letters next to each other.
'all'+'clear'='ALL-CLEAR'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for all clear that I've seen before include "Message confirming safety" , "ARP signal" , "reassuring signal" , "Signal that it's safe to come out" , "Signal to resume normal activities" .)