Unfeeling plight came unexpectedly (10)
I believe the answer is:
phlegmatic
'unfeeling' is the definition.
(thesaurus)
'plight came unexpectedly' is the wordplay.
'unexpectedly' is an anagram indicator.
'plight'+'came'='plightcame'
'plightcame' is an anagram of 'PHLEGMATIC'.
(Other definitions for phlegmatic that I've seen before include "dull and lifeless" , "Unexcitable" , "Unemotional" , "cool" , "Calm; philosophical" .)